YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 1
UNIT 1 HUMAN BODY SYSTEMS LESSON 1 THE MALE REPRODUCTIVE SYSTEM The functions of the male reproductive system: -To produce, store and transport sperm cells for reproduction; and to produce hormones that are needed for the development of secondary sex characteristics. The male reproductive system is made up of several organs. These organs perform specific functions.
Testes-are globular glands that is responsible for producing substances essential for production. It produces sperm cells which are male sex cells. It also produces the male hormone called testosterone. Hormones are chemicals that affect that affect different body processes Scrotum-a thin pouch that contains the testes and is located at the base of the penis. Epididymis-a coiled tubes where sperm cells pass through and stay to complete their maturation. Vas deferens- a long duct which is the passageway of the sperm cells from the epididymis to the urethra. Urethra- is the tube that conducts the sperm cells out of male‘s body.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 2
Accessory glands: Seminal vesicles- are saclike structures attached to the vas deferens to the side of the bladder. Prostate gland-produces a thin milky fluid, located at the base of the urethra. Cowper’s gland-are two small glands about the size of a pea. They are located on each side of the penis. They secrete a thick and clear fluid. Semen-the combination of sperm cells and all of these fluid. The process by which semen is released outside the body is called ejaculation. Penis-the male external organ. It is an elongated muscular organ with numerous tiny blood vessels.
LESSON 2: FEMALE REPRODUCTIVE SYSTEM Female Reproductive System Anatomy The female reproductive system includes the ovaries, fallopian tubes, uterus, vagina, vulva, mammary glands and breasts. These organs are involved in the production and transportation of gametes and the production of sex hormones. The female reproductive system also facilitates the fertilization of ova by sperm and supports the development of offspring during pregnancy and infancy.
Ovaries The ovaries are a pair of small glands about the size and shape of almonds, located on the left and right sides of the pelvic body cavity lateral to the superior portion of the uterus. Ovaries produce female sex hormones such as estrogen and progesterone as well as ova (commonly called "eggs"), the female gametes. Ova are produced from oocyte cells that slowly develop throughout a woman‘s early life and reach maturity after puberty. Each month during ovulation, a mature ovum is YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 3
released. The ovum travels from the ovary to the fallopian tube, where it may be fertilized before reaching the uterus. FallopianTubes The fallopian tubes are a pair of muscular tubes that extend from the left and right superior corners of the uterus to the edge of the ovaries. The fallopian tubes end in a funnel-shaped structure called the infundibulum, which is covered with small finger-like projections called fimbriae. The fimbriae swipe over the outside of the ovaries to pick up released ova and carry them into the infundibulum for transport to the uterus. The inside of each fallopian tube is covered in cilia that work with the smooth muscle of the tube to carry the ovum to the uterus. Uterus The uterus is a hollow, muscular, pear-shaped organ located posterior and superior to the urinary bladder. Connected to the two fallopian tubes on its superior end and to the vagina (via the cervix) on its inferior end, the uterus is also known as the womb, as it surrounds and supports the developing fetus during pregnancy. The inner lining of the uterus, known as the endometrium, provides support to the embryo during early development. The visceral muscles of the uterus contract during childbirth to push the fetus through the birth canal. Vagina The vagina is an elastic, muscular tube that connects the cervix of the uterus to the exterior of the body. It is located inferior to the uterus and posterior to the urinary bladder. The vagina functions as the receptacle for the penis during sexual intercourse and carries sperm to the uterus and fallopian tubes. It also serves as the birth canal by stretching to allow delivery of the fetus during childbirth. During menstruation, the menstrual flow exits the body via the vagina. The function of the external female reproductive structures (the genitals) is twofold: To enable sperm to enter the body and to protect the internal genital organs from infectious organisms. The main external structures of the female reproductive system include: 

Labia majora: The labia majora enclose and protect the other external reproductive organs. Literally translated as "large lips," the labia majora are relatively large and fleshy, and are comparable to the scrotum in males. The labia majora contain sweat and oil-secreting glands. After puberty, the labia majora are covered with hair. Labia minora: Literally translated as "small lips," the labia minora can be very small or up to 2 inches wide. They lie just inside the labia majora, and surround the openings to the vagina (the canal that joins the lower part of the uterus to the outside of the body) and urethra (the tube that carries urine from the bladder to the outside of the body). YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 4
Bartholin's glands: These glands are located beside the vaginal opening and produce a fluid (mucus) secretion. Clitoris: The two labia minora meet at the clitoris, a small, sensitive protrusion that is comparable to the penis in males. The clitoris is covered by a fold of skin, called the prepuce, which is similar to the foreskin at the end of the penis. Like the penis, the clitoris is very sensitive to stimulation and can become erect. Activity #1 Directions: Identify the words being described in the sentence. 1. The male external organ. 2. The tube that conducts the sperm cells out of male‘s body. 3. A coiled tubes where sperm cells pass through and stay to complete their maturation. 4. Are two small glands about the size of a pea. They are located on each side of the penis. They secrete a thick and clear fluid. 5. Produces a thin milky fluid, located at the base of the urethra. 6. The power factory of the sperm cell. 7. The male sex cells. 8. Globular glands that is responsible for producing substances essential for reproduction. 9. The system which function is to produce, store and transport sperm cells for reproduction. 10. The process by which organism produce offspring.
LESSON 3: CHANGES DURING PUBERTY Puberty is the period during which adolescents reach sexual maturity and become capable of reproduction. Changes during puberty differ between males and females. Physical changes Various bodily changes are associated with puberty. Boys and girls experience growth spurt, a stage of rapid growth due to the production of growth hormones. Growth spurt usually happens earlier among girls than boys. This is why at a certain age; girls tend to be taller than boys. Boys catch up usually when they become 14 years old. The sexual characteristics of boys and girls also change. These changes are stimulated and maintained by testosterone in males and estrogen in females. Changes in primary sex characteristics include nocturnal emissions or wet dreams in boys and menarche or the first menstrual cycle for girls. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 5
Boys commonly grow facial and body hair. They may develop deeper voices and Adam‘s apple may start to become more visible in some of them. Their biceps and chest muscles become more defined. Their shoulders become fuller and broader. Girls on the other hand, develop bigger breasts and wider hips. Mental and Emotional changes During puberty, boys and girls gradually develop to become young adults or adolescents, but they are no longer children. Adolescents are not yet full-grown adults, but they are no longer children. As a result, adolescents may experience‘‘ identity crisis‘‘ as they are caught between the roles of children and adults. Bodily changes also bring emotional stress to adolescents. Adolescents experience mental changes. They become more critical are more efficient in thinking compared to children. Their interest also changes. Moreover they start to establish close relationships with the opposite sex. A. Identify the changes that happen in boys and girls using the Venn diagram. Write only the numbers in the correct spaces. 1. Growth spurt 2 Widening of hips 3. Deepening of boys 4. Menstruation 5. Growth of hair in the genitalia
6. Appearance of pimples or acne 7.enlargement of breasts 8. Growth of facial hair 9. Emotional stress 10.broadening of shoulders
Changes in boys
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Changes in girls
Page 6
LESSON 4: THE MENSTRUAL CYCLE
What is a menstrual cycle? The menstrual cycle is the series of changes a woman's body goes through to prepare for a pregnancy. About once a month, the uterus grows a new lining (endometrium) to get ready for a fertilized egg When there is no fertilized egg to start a pregnancy, the uterus sheds its lining. This is the monthly menstrual bleeding (also called menstrual period) that women have from their early teen years until menopause, around age 50. The menstrual cycle is from Day 1 of bleeding to Day 1 of the next time of bleeding. Although the average cycle is 28 days, it is normal to have a cycle that is shorter or longer.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 7
Girls usually start having menstrual periods between the ages of 11 and 14. Women usually start to have fewer periods between ages 39 and 51. Women in their 40s and teens may have cycles that are longer or change a lot. If you are a teen, your cycles should even out with time. If you are nearing menopause, your cycles will probably get longer and then will stop. Talk to your doctor if you notice any big change in your cycle. It's especially important to check with your doctor if you have three or more menstrual periods that last longer than 7 days or are very heavy. Also call if you have bleeding between your periods or pelvic pain that is not from your period. What controls the menstrual cycle? Your hormones control your menstrual cycle. During each cycle, your brain's hypothalamus and pituitary gland send hormone signals back and forth with your ovaries. These signals get the ovaries and uterus ready for a pregnancy. The hormones estrogen and progesterone play the biggest roles in how the uterus changes during each cycle.
Estrogen builds up the lining of the uterus. Progesterone increases after an ovary releases an egg (ovulation) at the middle of the cycle. This helps the estrogen keep the lining thick and ready for a fertilized egg. A drop in progesterone (along with estrogen) causes the lining to break down. This is when your period starts. A change in hormone levels can affect your cycle or fertility. For example, teens tend to have low or changing progesterone levels. This is also true for women close to menopause. That is why teens and women in their 40s may have heavy menstrual bleeding and cycles that change in length. Other things can change your cycle. They include birth control pills, low body fat, losing a lot of weight, or being overweight. Stress or very hard exercise also can change your cycle. Pregnancy is the most common cause of a missed period.
LESSON 5: HUMAN FERTILIZATION AND DEVELOPMENT Fertilization is the union of an egg sperm cell and an egg cell. A zygote or fertilized egg is formed after this process.
After fertilization, the zygote travels along the fallopian tube to get to the uterus. It undergoes cell division while it travels. This single cells become two. At this stage, the fertilized egg is called a blastomere or blastula. It then becomes a ball of cell known as morula. Upon reaching the uterus it becomes a blastocyst. The blastocyst undergoes further cell division and
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 8
differentiation to become an embryo. The term embryo refers to any developing organism whose body form is not yet recognizable.
A fluid-filled sac protects the embryo. This is called the amniotic sac. Its fluid is called amniotic fluid, keeps the embryo moist. A mass of blood vessels called the placenta transport nutrients and oxygen from the mother to the embryo. The embryo is connected to the placenta through a tube called umbilical cord. Waste from the embryo is also carried away by passing through this route to the mother‘s blood for excretion.
A. Write true if the statement is true. If the statement is incorrect change the underlined word(s) to make it correct. Write your answer on the blank before the number. _________1.A female has thousands of egg cells upon birth. _________2. An egg cell leaves the ovary when it is mature. _________3. Fertilization usually happens in the fallopian tube. _________4. The fertilized egg is called an embryo. _________5.The umbilical cord attaches the embryo to the fallopian tube. _________6.Placenta transports nutrients and oxygen from the mother. _________7.Girls usually starts to have menstruation at the age between 11 and 14.
LESSON 6: COMMON SEXUALLY TRANSMITTED DISEASES AND REPRODUCTIVE ORGANS DISORDER Sexually Transmitted Diseases
Chlamydia- a common bacterial infection that can be passed on through sexual contact. Men who are infected with this experience a burning sensation when urinating. It is also characterized by penile discharge. Women may experience abdominal pain, vaginal discharge and bleeding between menstrual periods. If left untreated women may develop pelvic inflammatory disease, which may cause infertility or complicated pregnancy.
Gonorrhea is a disease caused by bacteria that attack the lining of the genitalia and other surfaces, such as the throat and the eyes, which are lined with mucus membrane. Its symptoms are also similar to that of Chlamydia.
Genital herpes is caused by a virus called herpes simplex virus(HSV) .The virus causes painful sores and blisters on the genitalia. There are anti-viral drugs that can control the symptoms. However , the virus remains in the body for life.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 9
Syphilis is a bacterial infection that causes open sores on the genital organs and other body parts. If not treated ,syphilis may affect other organs in the body such as the heart, lungs and brain .Penicillin can cure the infection.
Genital warts are viral infections that appear on the genital organs or the anus. Painless bumps that grow on the genital area can be removed by minor surgery. Medications that are applied externally can also remove genital warts.
Acquired immunodeficiency syndrome (AIDS) is a deadly STD.
It results from the infection with the human immunodeficiency virus (HIV). AIDS weakens the body‘s resistance. The body loses its ability to fight even the simplest infection. Sexual contact is the most common way of transmitting HIV. Blood Transfusion from an infected donor is another way. Moreover, during syringe injection or tattoo making by using the needles previously used by an infected person. Common Reproductive Disorders
Ovarian Cysts are small sacs filled with fluid. These cyst found in the ovary maybe harmless and may degenerate themselves.
Infertility is the inability of a female to get pregnant or the incapability of a, male to reproduction
Premenstrual Syndrome (PMS) is a collection of physical and emotional stresses or symptoms related to the menstrual cycle
Prostate Cancer starts when cancer cells or abnormally growing cells grow in the prostate gland.
A. Identify the reproductive diseases or disorder characterized by the following symptoms. 1. Growth of painless bumps on the genital area.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 10
LESSON 8: PARTS OF THE RESPIRATORY SYSTEM
Respiration is the process by which an organism takes oxygen and release carbon dioxide. Two phases of respiration:  
External respiration- is the exchange of gases between the body and the atmosphere. Internal respiration is the exchange of gases between body tissues.
Upper respiratory tract: nasal cavity, pharynx and larynx Lower respiratory tract is composed of the trachea, lungs, bronchi, bronchioles and alveoli. Nasal Passages Nose the hollow air passage in the uppermost portion of the respiratory system. Its two openings called nostrils, serve as entrance to the nasal cavities. Nasal cavities are hollow spaces that connect the nostrils to the upper respiratory tract. Cilia are tiny hairs whose function is to filter dust particles that enter the nose. The mucous membrane produces mucus, a sticky, thick and moist fluid that traps potentially disease-causing particles that may enter the lungs. Pharynx connects the mouth cavity and the nasal cavity. if the nasal passages are clogged, air can still reach the lungs through the mouth. Pharynx serves as
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 11
passageway for food and air. It leads to two tubes: the esophagus, which is connected to the stomach; and the trachea which is connected to the lungs. The tonsils are structures found on both sides of the pharynx.They block and destroy the bacteria from inhaled air and swallowed food. Larynx It is located near the middle of the neck. It delivers air to the trachea. It is also responsible for producing sound it is also called the ‗‘Voice box‘‘. There is a thin leaflike tissue attached to the front and top of the larynx called epiglottis. Trachea Is also known as windpipe. It is made up of 15 to 20 cartilage rings. These rings hold the trachea open, enabling air to pass through all the time. Lungs Are the main organs of the circulatory system. Humans have two lungs, which supply oxygen to the blood in exchange for carbon dioxide. The lings expand when one is breathing and in contract when one is breathing out. The rib cage protects the lungs from injury Bronchi, bronchioles and Alveoli The trachea branches into two tubes, the left and the right bronchi (pl. bronchus).The bronchi are embedded into the lungs. They branch into smaller tubes called bronchioles. The bronchioles lead into balloon like air sacs called alveoli (si. alveolus).It is the site of gas exchange. There are about 150 million alveoli in each lung. Each alveolus has thin walls that are covered with tiny blood vessels called capillaries. A. Identify the term being described in each sentence. Write your answer on the blank. 1. This is the passageway that connects the nostrils and the upper throat. 2. It is called the voice box. 3. These are hairlike structure that filter the air. 4. It prevents food from entering the lungs. 5. It is where the exchange of ases happens. 6. These are the two openings of the nose. 7. It is the passageway for food and air. 8. It is also known as windpipe. 9. These are the main respiratory organs of the body. 10. This is a sticky substance that traps dust from inhaled air YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 12
LESSON 12: PARTS OF THE URINARY SYSTEM
The Kidney The Parts and Function of the Urinary System Our body is like a machine. Machine needs oil or gasoline to work. Our body needs food in order to carry out its activities. Once the food has reached the body systems, they are quickly used for energy. In the process, wastes materials are produced which need to be removed from the body. The solid waste material comes out through the anus, while the fluid material is eliminated through the urinary system. The Urinary System and Its Major Parts 1. Kidneys- the kidneys are two brownish, bean shaped organs about the size of a fist, they weigh about 5 ounces. They are located in the upper right and left back part of the abdominal cavity. Each kidney contains about 1,200,000 microscopic filters called nephrons. Nephrons are smaller than the smaller dots. The main function or the kidneys are to maintain the water balance and to eliminate waste materials from the blood.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 13
2. Ureters – the left and the right ureters are long muscular tubes. They are about 12 inches long with a diameter 2 to 3 millimeters. The ureters connect pelvis of each kidney to urinary bladder. They carry urine from each kidney to the urinary bladder. 3. The Urinary Bladder – the urinary bladder is a muscular sac that holds urine. It is located in front the pelvis and behind the pubis. As the bladder fills walls stretch signaling the desire to urinate. 4. The Urethra- the urethra is a muscular tube which carries urine from the bladder to the outside part of the body. In the female, it is a one inch long from the bladder to the cleft of the labia. In the male, it is several inches long from the prostate gland to the penis. When one is about to urinate, a value in the urethra relaxes to allow the urine to flow out. The Urinary System Cleans the Blood Waste Products During normal activity of the body, waste product are formed. The chief waste of the body are carbon dioxide, water, urea and salts. Carbon dioxide is eliminated through the lungs while water, urea and salts are eliminated through the urine. Urea is a product resulting from the breakdown of protein foods and of protoplasm. It is excreted mainly but the kidneys. Urinary Systems Mechanism Glomerulus – each nephron is composed of a glomerulus. The glomerulus is surrounded by hollow capsule known as Bowman‘s Capsule. The capillaries in the glomerulus filters the waste materials of the blood except protein and the cells. 2. Filtered Fluid – the filtered fluid enters the bowman‘s capsule, where it flow down through its twisted tubes. The walls of the tubes absorb back in to the blood the needed water and blood chemicals. 3. Pathway of Unwanted Chemicals – Unwanted chemicals are discharged. The unwanted chemicals are the waste products. They come out in the form of urine. The urine passes into the ureter and on to the urinary bladder. And the urethra which releases it to the outside of the body. Urine gives valuable clues to the body. Sugar in the urine is an indication of diabetes. Albumen may signify that the kidneys are not functioning properly. 1.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 14
The nephrons
QUIZ: Urinary System
1. The "A" arrow points to the: adrenal gland cortex ureter glomerulus 2. The arrow "B" points to the: cortex renal pelvis medulla bowman's capsule YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 15
3. After blood enters the kidney, it travels to the: proximal tubule distal tubule collecting duct glomerulus 4. The proximal and distal tubule are separated by the: glomerulus loop of henle renal artery collecting duct 5. Urine is stored in what part of the kidney before it moves to the bladder renal pelvis ureter medulla loop of henle 6. What tube carres urine outside the body from the bladder? ureter distal tubule urethra loop of henle 7. Which of the following is NOT a job of the kidneys? keep the volume of water in your body constant secrete hormones regulate blood pressure remove wastes 8. The kidneys are located: on either side of the lung dorsal to the liver
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 16
within the mesentery of the small intestine near the middle of the back, on either side of the spine 9. The structure labeled "B" is the: cortex bowman's capsule collecting duct nephron 10. The structure labeled "G" is the: renal artery renal vein proximal tubule distal tubule
LESSON 13: HOW OTHER BODY WASTE ARE EXCRETED
1. Lungs
Cellular respiration is necessary to provide our bodies with energy as without it, the body‘s cells will die. However, cellular respiration produces the waste product of carbon dioxide which then needs to be eliminated from the system. This carbon dioxide diffuses out from the cells in the body, entering the bloodstream and eventually going to the lungs. The lungs contain alveoli which diffuse the carbon dioxide from the blood so it can enter the lung tissue and eventually leave the body during exhalation.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 17
2. The Skin
Sweat is a crucial part of the excretory system as it is responsible for eliminating sweat from the body. Salt contains several metabolic wastes including urea, salts and water. In addition to excreting metabolic wastes, sweat also cools down the body. The sweat glands are able to receive the various wastes because they are mixed in with capillaries, which are tiny blood vessels. This means that the wastes can diffuse out of the blood and enter the sweat glands before passing out of the skin in the form of sweat. 3. Large Intestines
The large intestine is around 5 feet in length and is responsible for transporting waste so it can be excreted. In general, it collects waste from all over the body and then extracts usable water, allowing for the removal of solid waste. It does so because any waste products or food that the small intestine doesn‘t absorb will enter the large intestine. Once it is there, bacteria, water and undigested food are combined to create feces. Sometimes it will take food 24 hours to complete its journey through a person‘s large intestine.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 18
4. The Liver
The liver is responsible for detoxifying and breaking down any toxins such as chemicals and poisons that enter our bodies. One of the ways in which the liver fulfils this function is by taking ammonia in its poisonous form and converting it into urea which the kidney will eventually filter, creating urine. In addition, the liver produces bile which the body then uses to help break fats down into unusable waste and usable fats. Bile is stored in a person‘s gall bladder after the liver produces it. The small intestine uses it to break down acidic wastes such as ammonia as well as fats and ethanol, converting them into harmless substances. The liver also serves several functions within the circulatory system. It is also responsible for maintaining the body‘s proper levels of glucose based on cues from insulin (which increases the amount of glucose stored) and glucagon (which decreases the amount of glucose stored). The liver also helps detoxify the blood by removing any chemicals that are potentially hazardous.
LESSON 14: COMMON AILMENTS OF URINARY SYSTEM NEPHRITIS Definition: Nephritis is the inflammation of one or both kidneys. Herein the organs of body get affected through autoimmune disorders. Out of the disorders, lupus nephritis is a potentially serious condition. In this, the auto immune system of the body attacks body tissues, organs and body cells. The result is pain at the start and body organ damage for continued diseases.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 19
Causes: This is caused by the inflammation of the first part of nephron (the basic kidney unit), which is called glomerulus. Symptoms: Smelly urine Pain in lower abdomen Blood in urine Treatment: Antibiotics can be used to treat this condition. When the disorder is caused by lupus, steroids may also have to be used. KIDNEY STONES Definition: These are smaller sized deposits of calcium and can be seen in the nephrons. The stones could also increase or go down to urinary tract causing extreme pain. The stone may also get infected causing further set of complications Causes: The main cause is change/increase in salt and mineral levels and that of other substances in urine. This may later on cause coagulation and increase size of stones. The other reason can be heredity. Symptoms: Vomiting or nausea Painful urination Frequent urination Fever or chills Bloody or smelly urine Sharp pain of the back or the side Treatments: Reduced size of stones tends to pass out of body without requiring any surgery. The treatment may consist of just taking lot of fluids so that the stones are washed down. In such cases, the fluid is collected for 24 hours continuously and examined in laboratory for presence of small stones. Painkillers may also be used for alleviation of pains for the patient.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 20
BLADDER CANCER Definition: When there is uncontrolled growth of cells present in bladder, it is known as bladder cancer. The end result is a tumor in the bladder. Causes: The cause and effect in case of cancer is not yet very clear but a number of reasons are cited for this purpose and most of them are smoking, radiation, parasitic infection, exposure to chemicals known as carcinogens. Symptoms: Pain while urinating Back pain Pain in pelvic region Frequent urge for urination without actual flow or frequent urination Blood in urine Treatments: The treatment of cancer bladder is similar to the other cancers of the body. Intravesical therapy, radiation therapy, or chemotherapy is applied coterminous with the surgery. The exact sequence is best determined by the opinion of the treatment and there is no definite line of standard treatment developed in any of countries anywhere in the world. URINARY TRACT INFECTION A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra. Women are at greater risk of developing a UTI than men are. Infection limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys. Antibiotics are the typical treatment for a UTI. But you can take steps to reduce your chance of getting a UTI in the first place. Symptoms Urinary tract infections don't always cause signs and symptoms, but when they do they may include: A strong, persistent urge to urinate A burning sensation when urinating Passing frequent, small amounts of urine Urine that appears cloudy YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 21
Urine that appears red, bright pink or cola-colored — a sign of blood in the urine Strong-smelling urine Pelvic pain, in women Rectal pain, in men
Types of urinary tract infection Each type of UTI may result in more-specific signs and symptoms, depending on which part of your urinary tract is infected. Part of urinary tract affected Kidneys (acute pyelonephritis)
Signs and symptoms
Bladder (cystitis)
Pelvic pressure Lower abdomen discomfort Frequent, painful urination Blood in urine
Burning with urination
Urethra (urethritis)
Upper back and side (flank) pain High fever Shaking and chills Nausea Vomiting
Activity 1.Multiple choice 1. A tube that carries urine from the bladder to the outside of the body. A.ureter B.Urethra C.Nephron 2. Largest organ of the body that gives off bodily sweat and perspiration. A.kidney B.Bladder C.skin 3. The organ that collects and stores urine excreted by the kidneys before it is disposed of by urination. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 22
A.Urethra B.Nephron C.Bladder 4. A cluster of capillaries in the kidneys. A.glomerulus B.ureters C.Nephrons 5. Filtering of the blood takes place in these areas. A.ureters B.Intestines C.Nephrons 6. The two major organs of the excretory system. A.ureters B.Kidneys C.Ovaries 7. What is the excretory system in charge of? A.Breaking down food so it can be used by the body. B.Giving the body support and strength C.Removing wastes and excess fluid from the body 8. These are muscular ducts that propel urine from the kidneys to the urinary bladder. A.Arteries B.veins C.Ureters Activity 2. Complete the table below. Ailment of the Symptoms Urinary System
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Causes
Remedy or Cure
Page 23
CHAPTER 4 CLASSIFICATION OF LIVING THINGS LESSON 15: INTRODUCTION TO TAXONOMY Living Things are classified based on their similar characteristics. Taxonomy is the science that deals with identifying, grouping, and naming organisms. In ancient time, the Greek philosopher Aristotle classified organisms as either plants or animals. Based on his classification, plants were grouped according to the structure of their stems-as herbs, shrubs, vines or trees. Animals were classified as water animals, land animals or aerial animals. However, many organisms did not fit in Aristotle‘s classification. They were neither plants nor animals. The Swedish botanist Carolus Linnaeus is regarded as the father of taxonomy, as he developed a system known as Linnaean classification for categorization of organisms and binomial nomenclature for naming organisms. This modern classification uses kingdom as the biggest group of organisms. This modern classification uses kingdom as the biggest group og organisms.A kingdom can be divided into different phyla,a phyla into classes, a classinto orders, an order into families a family into genera, and finally a genus into species. In modern classification, humans and tigers are both grouped under the kingdom Animalia. They both have backbones, so they both belong to the phylum Chordata. They both have mammary glands, so they are grouped under the class Mammalia. However they do not belong to the same order. Humans belong to the order Primata, a smaller group that stand erect. Tigers belong to the order Carnivora, a group of animals that only eat meat. Table 4.1 Classification of Humans and Tigers Level of Classification Kingdom Phylum Class Order Family Genus Species
Human Animalia Chordata Mammalia Primata Hominidae Homo Sapiens
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Tiger Animalia Chordata Mammalia Carnivora Felidae Panthera Tigris
Page 24
Humans can further be classified based on the family, genus and species they belong to. The family Hominidae includes animals that are considered humanlike. The genus Homo refers to humans. The lowest level of classification is the species sapiens. According to this classification, sapiens refers to the present species of humans. Using the seven-level system in classifying organisms is laborious. Linnaeus devised the use of a two-word naming system to classify living things. An organism is classified and named using its genus and species. Humans are called Homo sapiens, while tigers are called Panthera tigris. The scientific names of organisms are derived based on this two-word naming system. Scientific names are in Latin. Linnaeus chose Latin because it was the universal language during that time. Activity I Identify the word or group of words that each statement describes. ___________1. This is the field of science that deals with identifying, classifying, and naming organisms. __________2. He classified organisms using a seven-level system. __________3. This is the scientific name of humans. __________4.It is the largest group of organisms based on the seven levels of classification. __________5. This is the language used in giving scientific names. Activity2. Make a mnemonic device to easily remember the seven-levels of classification. Example: King Philip Came Over from Great Spain K-_________ P-__________ C-_________ O-_________ F-_________ G-_________ S-_________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 25
LESSON 16: KINGDOMS OF LIFE Kingdom Monera Organisms that belong to the kingdom Monera are single-celled or unicellular organisms. These organisms are microscopic. Regardless of their size, they can carry out life activities, such as reproduction and growth, like other living things do. In some cases, they group together to form colonies. Bacteria are common representatives of kingdom Monera. They exist almost everywhere. They can be found in water , air, soil, food and even inside the bodies of animals and plants. They reproduce very fast. This is why many infections caused by bacteria spread rapidly. However some are beneficial to humans. Some are sources of medicines , moreover decomposers break down dead plants and animals into simpler substances that can be reused by other organisms.
Figure 4.2 Bacteria Bacteria are classified into three groups based on their shapes. Cocci are spherical or globular- shaped bacteria. Bacilli are cylindrical or rod-shaped bacteria. Corkscrew or spiral-shaped bacteria are called spirilla.
Cocci
bacilli
spirilla
Cyanobacteria or blue-green algae are also members of the kingdom monera.Similar to plants and plantlike protists, cyanobacteria make their own food. They live in places where there is enough moisture. The kingdom Monera has been divided into two kingdoms-Eubacteria and Archaebacteria.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 26
The kingdom Eubacteria consists of large group of bacteria that are knowns as the ‗‘true bacteria‘‘, because they are the most common bacteria that exist today.This includes disease-causing bacteria and decomposers. The kingdom Archaebacteria consists of the most primitive types of bacteria. These bacteria are able to live in a variety of places. Some archaebacteria can live in places with extremely low or extremely high temperatures. Some live in a very acidic environment. Kingdom Protista The kngdom Protista includes both unicellular and multicellular organisms. Protists differ in cellular structure from monerans.The kingdom Protista includes animal-like protists and plantlike protists. Animal-like Protists( Protozoans) Protozoans are unicellular animal-like protists.They cannot make their own food.Like animals, the depend on other organisms for food. Protozoans are grouped according to how they move. Sarcodes move and take using their false feet or pseudopods. A Sarcode surround its food before taking it inside its body. This manner of eating is called phagocytosis.The amoeba is an example of a sarcode.
Figure 4.5 How an amoeba take its food Ciliates use their hairlike structures to paddle back and forth in water. The paramecium is n example of a ciliate. It uses its cilia to move and sweep food into its body.
Figure 4.6. A paramecium moves using its cilia Flagellates move by using their one or more whiplike structures called flagella. Some flagellates live inside the body of other organisms. Others inhabit freshwater areas. Some flagellates are harmful ,they can cause diseases. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 27
Trypanosomes, which causes the African sleeping sickness. This disease is transmitted by the tsetse fly. When bitten by a tsetse fly that carries trypanosomes, a person experiences high fever and sleepiness.
Figure 4.7. trypanosomes Sporozoans are protozoans that cannot move on their own .Most sporozoans cause diseases in humans and animals. Plasmodium, the most common causes malaria. Female anopheles mosquitoes are the carriers of this disease. Once a carrier mosquito bites a person or an animal ,it injects plasmodia into the blood of the person or animal. The plasmodia destroy blood cells. The afflicted person experiences chills, high fever, and in worse cases,anemia and kidney failure which may eventually lead to death.
Figure 4.8 A plasmodium Plantlike Protists ( Algae) Algae are plantlike protists that have chlorophyll, a green pigment found also in plants.This enables them to make their own food .By doing so,they also release oxygen to the surroundings.In fact, 90% of oxygen on earth is supplied by plantlike protists. Are unicellular, while others are multicellular Some algae contain pigments aide from chlorophyll.Some of them appear as green,red, or brown. Euglenas and Dinoflagellates are able to move using tail-like structures.Diatoms have a tough cell wall that contains glasslike chemicals. Diatoms cannot move.
Figure 4.9 Diatoms and a euglena YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 28
The sea lettuce is a multicellular alga. It grows in marine water. Kelps are multicellular alga that are edible to humans and other animals.
Figure 4.10 Sea lettuce and kelps Kingdom Fungi Fungi are mostly multicellular organisms. Some members such as mushroom, are often mistaken for plants. They have cell walls like plants do. However, unlike plants , fungi cannot make their own food because they do not have chlorophyll. They get their nutrition from other organisms.
Figure 4.11. Mushrooms are fungi Some fungi are beneficial to humans. Some of them, like the mushroom tengang daga, are edible. Yeasts are fungi. Yeasts are used in making bread. They are also used in fermentation processes like in making wine.
Figure 4.12 The tengang daga is an edible fungus. Fungi can also be good sources of medicine. Penicillin, which is known as a ‗‘wonder drug,‘‘ is produced by a group of fungi called molds. However, there are also fungi that are harmful. Some, like the death cap, are poisonous .There are also fungi that can cause different diseases not only in humans YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 29
but also in animals and plants. In humans, diseases such as athlete‘s foot and ring worm are caused by fungi.
Figure 4.13.The death cap is a poisonous fungus Activity I Read each statement carefully. Write true on the blank if the statement is correct; write False if it is incorrect. _______1. Members if the kingdom Monera are mostly unicellular organisms. _______2. Mushrooms are multicellular fungi that can make their own food. _______3. Algae are protists that have chlorophyll. _______4. Most of the earth‘s oxygen supply comes from plantlike protists. _______5.The drug penicillin comes from beneficial bacteria. Activity II To which kingdom does each organism belong? Write the name of each organism in the correct column. Kelp dinoflagellate lactobacillus diatom Mushroom yeast amoeba plasmodium Trypanosome mold Kingdom Monera
Kingdom Protista
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Kingdom Fungi
Page 30
LESSON 17: WHERE ANIMALS LIVE Animals are all around us. They are found in different places. The place where an animal lives is called habitat. Animals have different adaptations that help them survive in their habitats. Forests Forests house most plants and animals on Earth. They are distinguished by other habitats by a dense growth of trees. Animals in different types of forest have different adaptations. Animals in temperate forests are adapted to experiencing four seasons. Some animals store food and borrow underground during the cold season. Other animals may go to warmer places and return when the season becomes warmer and the food becomes more abundant. Some sleep for a long time in winter and become more active during the warmer seasons .Animals that live in these types of forests include bears, raccoons , rabbits, deer and squirrels. Animals in rainforests are used to warm and wet climate. They are adapted to living in certain parts of rainforests. Some are adapted to living on trees, while others stay on the ground. Rainforest animals include monkeys, jaguars, birds and many types of insects. Grasslands The grassland is a grassy, windy, and partly dry habitat. Many animals in grasslands are grazing plant eaters. The abundant supply of grass serves as their main food source. Grassland animals of this type include zebras and bison. There are also grassland animals such as lions and cheetahs, which hunt other animals for food.
Mountains Animal in mountains are adapted to moving on steep cliffs and barren rocks And to little plant life. They are also used to cold temperatures and low oxygen. Some of these animals have thick woolly fur to survive the cold. Others have strong hooves that help them move around, jagged rocky slopes. Example f these animals are mountain goats and mountain lions. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 31
Deserts Most desert animals are adapted to the scarcity of food and water. Many of them do not need to drink for a long time. Animals such as camels, foxes, scorpions and centipedes get the water they need from the plants, seeds or animals they eat. Some desert animals survive the heat by hunting food at night and hiding by borrows during the day.
Polar Regions These habitats are treeless and experience frigid winters. The ground is covered with ice all year round. This permanent frozen layer of soil is called permafrost. Most animals in this type of habitat have insulating feathers or fur that keeps their body warm. For example , polar bears have white coats with thick ,waterproof underfur that covers their whole body. This enables them to swim in icy water. Other animals in these habitats include penguins, seals, snowy owls, and caribou.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 32
Bodies of Water Many animals are adapted to living in different bodies of water. They are found in seas and oceans. Fish have gills and fins that allow them to breathe and move in the water. Dolphins have blowholes that enable them to breathe as they go to the surface from time to time. Animals are also found in freshwater habitats such as lakes, rivers and streams. Examples of these animals are alligators, hippopotamuses, and freshwater fish. There are also animals in estuaries. This type of habitat is where freshwater and seawater meet. They serve as nurseries for many fish such as salmon and eels. They are abundant with worms, crabs and snails. Many birds live near bodies of water where they can get easily their food.
Activity 1 Which of the animals listed below does not belong to the group? Cross out the name of the animal. Write on the blank the habitat common to the animals that are left in each set. Camel
Butterfly
Polar bear
Cow
Jaguar
Turtle
Caribou
Leopard
Dolphin
goat
shark
starfish
1._____________
4.__________
2.____________
Sponge
Panda
Rattlesnake
Owl
Coyote
Snow
Sidewinder
Leopard
(snake)
Arctic fox
3.__________
5.________________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 33
LESSON 18: HOW ANIMALS GET AND EAT THEIR FOOD Animals eat different kinds of food. Based on the food they eat , animals may be classified into hervibores, carnivores and omnivores. 1. Herbivores- Animals that only eat plant. They have flat and broad teeth for grinding and gnawing of leaves, soft stems and other plant parts. Cows, horses, beavers, caribous and are herbivores. Herbivora is derived from the Latin herba meaning a small plant or herband vora, from vorare, to eat or devour. A herbivore is an animal that gets its energy from eating plants, and only plants. Many herbivores have special digestive systems that let them digest all kinds of plants, including grasses.
2. Carnivores- are animals that eat only animals. Tigers, jaguars, leopards and wolves have sharp, pointed teeth and claws for tearing meat. Some birds such as falcons, hawks and eagles have sharp beaks and talons to catch other animals. Scavengers are animals that feed on dead animals. Examples of scavengers are hyenas and vultures. Moles, aardvarks and other animals that feed on insects are called insectivores.
3. Omnivores are animals that eat both plants and meat. These animals have both flat and sharp teeth. Pigs and bears are classified as omnivores.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 34
Animals have different body parts for getting and eating their food. The kind of food they eat can be determined from the structures of the body parts they use for eating.
Some insects , such as grasshoppers and praying mantises, eat leaves. They have mandibles for cutting and grinding leaves.
Butterflies, mosquitoes, and bees use a sucking tube called proboscis.
Animals that eat insects also have special body structures.
Frogs have legs for jumping far and high. They also have a long and sticky tongue to catch insects. Spider spin webs to trap insects.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 35
Some spiders can paralyze insects by biting them. Some marine animals such as jellyfish, squids and octopuses, have tentacles to grab small fish and smaller marine animals.
Sponges are animals that live on the ocean floor. They have a porous body that allows water to pass through and filter out food. Crabs have pincers for grabbing their food.
Birds that eat insects have thin ,long, and pointed beaks to reach insects in tree holes. Birds that eat seed fruits have short and strong bills to open the fruits. Water birds have bills that can scoop into the water when they dive to get their food. Birds that eat smaller animals have sharp and pointed beaks. Elephants use their trunks for uprooting chunks of grasses and for pulling out branches and leaves. Lions and tigers use their sharp claws to catch other animals.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 36
Activity 1. Identify the body parts that each of these animals uses to get their food. _____ 1. woodpecker _____ 2. lobster _____ 3. anteater _____ 4. honeybee _____ 5. turtle _____ 6. jellyfish _____ 7. Monkey _____ 8. house lizard _____ 9. lion _____ 10. elephant Activity 2. Classify each animal as herbivore, carnivore or omnivore. ________1. raccoon ________2. carabao ________3. gecko ________4. elepant ________5. hyena ________6. crow ________7. jackal
LESSON 19: HOW ANIMAL PROTECT THEMSELVES 
Specialized Body Parts
A pangolin will roll up into a ball-like shape to protect itself For example in this case we are taking a pangolin as an animal that can protect itself from danger. A pangolin will roll up into a ball like shape to protect itself as its behaviour besides it has a hard scales as its special characteristics to protect itself. Animals have different physical characteristics that protect themselves from their enemies. These include: a) a hard shell
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 37
b) thick skin c) dry, hard scales d) horns e) spines f) sharp claws
Tiger have sharp claws to fight-off and injure their enemies
The bodies of garden snails, clams, crabs and tortoises are covered by a hard shell. The shells help them to protect their enemies. Garden snails and tortoises can also pull their head, legs or their whole bodies inside their shell. Clams protect themselves by closing up their shells.
Porcupines, porcupine fish and starfish have spines on the surface of their body. The spines can injure enemies that go near or attack these animals. a) Porcupines raise their long, stiff spines as a warning when their enemies go near them. b) A porcupine fish can inflate its body by drinking a lot of water. This raises the sharp spines on the fish‘s body. The spines help to keep the fish‘s enemies away. Some animals have body shapes or colours that match their surroundings. This makes it easier for these animals to hide from their enemies.
Mimicry Some animals use their physical and behavioural similarities with other animals in order to protect themselves. a) Leaf insects have green body parts that look like leaves. b) Sticks insects have a long, thin body that look like a stick or twig. Their body colour is also similar to the colour of twigs. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 38
c) Zebras have black and white stripes on their bodies. This makes it more difficult for their enemies to spot them from a distance. Chemical defense Wasp defends themselves using their poison Squid can give off black ink that darkens the water around to confuse their enemies
Camouflage
Chameleon can change their skin colour to match the colour of their surroundings, for example, the colour a tree trunk. This ability helps chameleons to hide from their enemies. Some beetles and millipedes pretend to be dead when they are attacked or threatened. Also the arctic fox can change the colour of its fur to match the colour of its surrounding. In spring and summer, the arctic fox has grey fur. Before the start of autumn and winter, its fur will change to white. By changing the colour of its fur, the artic fox can avoid being detected by its enemies easily.
Countershading
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 39
Countershading applies when the upper and lower sides of an animals‘ body have contrasting coloration. Some animals such as bottlenose dolphins use countershading.

Deception Some animals protect themselves by deceiving their enemies
Peafowls spread their tails to ward off their enemies Elephants, deer, buffaloes and zebras live and move from place to place in groups (herds). This allows them to defend themselves together when they are in danger. For example, when predator tries to attack the young of the elephants, the adult elephants will form a circle and keep their young in the centre of the circle.
Besides, animals on earth live in many different habitats. Some of these habitats may be very hot or very cold. Animals that live in very hot habitats include camels and hippopotamuses. Animals that live in very cold habitats include whales and polar bears. Such animals have to adapt to the extreme weather in order to survive. The animals have special characteristics to protect them from extreme weather. These include: a) thick layer of fat under the skin b) thick fur YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 40
c) wrinkled skin d) food and water stored in the form of body fat Animals living in very cold habitats have a thick layer of fat under their skin.The whales, dolphin, polar bear and penguin keep their body warm with the help of the fat under their skin.

Adaptation to seasonal changes
Some animals have special behavior that helps them to adapt to very hot or cold weather conditions. These include: a) wallowing in mud or water b) migrating to a new habitat c) hibernating Some animals wallow in mud or water to keep their body cool on hot days. Buffaloes and rhinoceroses wallow in mud to keep their body cool on a hot day. Hippopotamuses wallow in water, for example in a river or lake to keep their body cool. This behavior also helps them to reduce loss of water from their body. Swallows and white storks adapt to changes in the seasons by migrating to new habitats. These birds migrate to warmer regions before when the place that they are living in starts to experience winter. During winter, the habitats of these birds will be very cold. It is also very difficult for these birds to find food or water during winter. By migrating to warmer regions, these birds avoid dying of cold or hunger. The special characteristics and behavior that protect animals from their enemies and extreme weather are important for their survival. In nature, stronger animals often kill weaker animals for food. For example, eagles kill rabbits and rat for food. Lions also kill zebras for food. So, weaker animals always have to protect themselves from stronger enemies in order to stay alive. Some animals such as zebras have to protect themselves against both their enemies and extreme weather. Some large animals such as elephants do not have natural enemies. However, they still have to protect themselves from their hot weather in their habitat to stay alive. During a drought, they have to move to new habitats to find water and food. Only animals that can protect themselves from their enemies and extreme weather will be survived in nature. Animals that cannot do so will be easily killed by their enemies or die of heat, cold or hunger. When all animals of the same type die, that type of animals will become extinct. Activity A. Cite an animal that uses the given protective adaptation. ___________1. Pincers __________6.camouflage YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 41
___________2. Talons ___________3. Spines ___________4. Deception ___________5. Countershading
__________7. chemicals __________8. mimicry __________9. antlers __________10. shells
B. What protective adaptation is used in the given situation? ___________1. A grasshopper blends with the color of the leaf. ___________2. The castniid moth looks like an ithomiine butterfly. ___________3. Dolphin appears as bright as the water as seen from the bottom. ___________4. Turtles hide their heads and legs inside their shells. ___________5. A salamander becomes inactive during summer days.
LESSON 20: THE VERTEBRATES One of the ways to study animals is to classify them into groups. Animals can be grouped into vertebrates and invertebrates. Animals with backbones are called vertebrates. Those without backbones are called invertebrates. FISH Fish are aquatic vertebrates. They have gills for breathing. Most of them have fins for swimming for moving easily in water. Scales cover the bodies of most fish. The bodies of fish are designed for moving easily in water. The swim bladder enables them to float on water at the desired depth. Using their specialized organ called lateral line. Fish can sense if there is an approaching predator before they can actually see it. This also helps them to detect nearby obstacles. Fish are ectotherms or cold-blooded animals. Their body temperature varies with the temperature of their surroundings. Fish can be classified as jawless, cartilaginous or bony fish. Amphibians Frogs and toads are classified as amphibians.Frogs have smooth skin and long limbs. Toads on the other hand, have warty skin and short limbs. Salamanders and caecilians are also amphibians. Salamanders have long slender bodies with tails. Caecilians the rarest amphibians, have no limbs. They look much like earthworms Look at figure 5.33. How are these animals similar to one another?
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 42
Salamander toad caecilian An amphibian‘s body is covered with moist and hairless skin.Amphibians have ectothermic bodies.This means that their body temperature changes with the surrounding temperature. They do not have the ability to regulate their body heat. Most amphibians lay their eggs in water .Their eggs are jellylike. The eggs dry out quickly when exposed to air. Once hatched ,these turn into tadpoles bearing gills and tails. As the tadpole matures, their gills are replaced by lungs. The tail change to limbs. These changes allows amphibian to become adapted to living both on land and in water. Most amphibians spend the first part of their lives in water, the second part on the land. Adult amphibians return to the water Reptiles
Reptiles are often called cold-blooded because they can't regulate their own body temperature. Their body temperature depends on the external temperature. They will lay in the sun to heat their body, or hide in the ground, under a rock or in water to cool their body. Crocodiles and alligators are large reptiles that spend much of their time on land and in water. They can walk on land using their webbed feet. They can also use YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 43
their long tail to swim in water. Crocodiles feed on large animals they catch on land or in water. They have powerful jaws and teeth to tear apart their prey. Lizards and snakes are the largest group of reptiles. Lizards are four legged animals with a long tail. Many lizards can shed their tail to escape from predators. They can then grow a new tail. Some lizards, such as the chameleon, can change colors to blend into their environment. This camouflage helps to protect them from predators. Birds
Birds are defined as winged animals with two legs that lay eggs. In addition to the wings, birds have two other easily recognizable characteristics. They are covered with feathers, and they have a beak with no teeth. Birds are warm-blooded animals, meaning that they internally regulate body temperature through processes such as controlling the metabolic rate. Birds are also classified as vertebrate animals. This means they have a backbone or spinal column. The birds ability to fly is what differentiates it from other types of vertebrate animals. There are over 10,000 species of birds. They range in size from the small hummingbird at 2 inches to the Ostrich standing 9 feet tall. Although all birds have wings, not all birds can fly. The penguin and ostrich are two well known birds that cannot fly. Birds live in almost all areas of the world, from the Arctic to the Antarctic. Many species of birds migrate at different times of year to take advantage of seasonal temperatures, availability of food sources, and breeding habitat. Although some birds such as the eagle or hawk live in small family groups, other birds live in large flocks. The flocks provide for safety in numbers to help fend off predators. Most birds are social animals, communicating with one another through calls and songs. Birds are nesting animals. Eggs are usually laid in a nest and incubated by the parents until the eggs hatch. Once hatched, most baby chicks live with parents for extended periods of time. Chicks depend on their parents for food and protection. As they grow older, young birds rely on their parents to teach them how to fly and catch food. Mammals
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 44
Mammals have several unique characteristics that differentiate them from other animals. Most mammals have hair, or fur, covering their body. They are also capable of regulating their body temperature. The mammals metabolism controls heat production, and the sweat glands help cool the body. These allow the mammal to maintain a constant body temperature, regardless of the environmental temperature. One other difference is that mammals give birth to fully formed babies, and the female mammals produce milk to feed their young. Most mammals walk on 4 legs, with only the humans walking upright on 2 legs. Aquatic mammals have flippers, or fins, for swimming rather than legs. Common mammals include: primates, such humans and monkeys; marsupials; rodents; whales; dolphins; and, seals.
Activity Guess the kind of animal that describes itself.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 45
_____________1. I live on land I cannot survive in water. I have hair on my skin. My body temperature does not change very much. _____________2 . I walk on two legs. I am endothermic . My body is covered with feathers. I lay eggs. _____________3. I live in water and on land. I lay eggs. I am cold-blooded. I have rough skin. _____________4. I live in water and breathe through my gills. I am coldblooded and have scaly skin. _____________5. I lay eggs. I live on land and in water. I have smooth skin. I am cold-blooded. LESSON 21: THE INVERTEBRATES Sponges Stages of Life
Most sponges are found in seawater, and only a few in fresh water. There are two basic forms in the life cycle of a sponge. Most sponges live their lives attached to a reef. Adult sponges are sessile.They don't move around . There was a time in their lives when they were little larvae that they were swimming around the water all by themselves. The word larva is another way to describe them when they are babies. Baby sponges don't look like adult sponges, so scientists use another word. Once the larvae land on a piece of rock, they take root (so to speak) and that's that, forever anchored. Sponges are really just a bunch of specialized cells working together to help the entire organism survive. Sponges do not have nervous systems, so they don't react to the world around them. Sponges are in the shape of a big "U." On the outside of the U are protective cells, but on the inside are these very special cells with little flagella (wildly whipping tail structures). Those flagella are constantly moving and keeping the water circulating inside of the sponge. Water is sucked in through holes/pores in the side of the sponge. We told you to remember the holes. When the water moves through the sponge, tiny food particles are filtered out of the water by the flagella. Then the water gets pushed out of the sponge through a hole called an osculum. That's basically the life of a sponge. Suck the water in, filter out the food, and send the water out. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 46
Cnidarians Anemone and coral are shaped with one end attached to something solid and the other end with tentacles moving out into the water. The shape is generally called a polyp form. Yes, even coral have that going on. When you think of a coral, you are probably thinking of a hard thing. That hard exoskeleton is what is left of the coral after it dies. When it is alive, hundreds of thousands of cells are alive and waiting for food to come by. Anemone and coral are an improvement on sponges. One big improvement is that they have a nervous system. That doesn't mean that they are thinking and planning how to catch food. It does mean that the whole organism can have a coordinated response. That response means if something happens in one part of the anemone, the rest of the anemone can act in a certain way. Maybe a fish is captured on the left side. The right side would then move over to help hold the fish so that it can't escape. They aren't thinking yet. They are acting based on a stimulus. The cnidarian family also has tissues. Tissues are specially developed groups of cells with one function. There could be tissue to digest food, tissue to help the anemone move, and tissue that helps the anemone stay attached to its rock. All of them work together and have specialized jobs. There seems to be a theme here regarding special cells. The cnidarians have one called a nematocyst. It's basically a little harpoon or spear that it shoots at passing prey. That harpoon has a poisonous protein that it injects into the prey to stop it from escaping. Nematocysts are also described as stinging cells. Those cells make it dangerous to touch anemone.
Flatworms
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 47
Flatworms are the simplest animals possessing heads. Their bodies are soft and flat with a single opening that serves as the mouth. They have eyespots on their heads. They have no anal opening. Most of the species are parasitic. They are super-primitive organisms that were the first to develop mesoderm. The big thing you should remember is that they are flat. There may be one more fact to remember. They are found in every environment that has water. Many scientists believe there are hundreds of species we will still discover. Tapeworms are always a nasty example. They live in intestinal tracts of many species. Cats, dogs, and even you could wind up with tapeworms. You'll also hear about flukes. It's another parasitic species that has a close relationship with man and other mammals. They are suckers in the flatworm family. Planaria are harmless flatworms that are often used in your biology labs. They are freshwater flatworms that have a head like an arrow. They're black with two white spots on their heads. Those spots are not eyes, but they do sense light. Flatworms have very simple nervous systems. Flatworms get most of their oxygen through diffusion. Since they have no specialized circulatory system, their flatness gives them a greater surface area to absorb more oxygen. There are species in many freshwater and saltwater environments as well as inside larger organisms. Since many flatworms are parasites, they have lifecycles in different hosts. Eggs many be deposited in the feces of one species. Another organism might eat those eggs and development begins in the digestive system. The flatworm might then mature in the muscle tissue. Flatworms can get around. Although really simple, flatworms have some advanced structures compared to some other animals. They were the first species to develop mesoderm. That mesoderm tissue develops into organs and muscles as the organism grows. They also have simple nervous systems and sensory organs. While they don't have a respiratory system or circulatory system to speak of, they do have a neat little digestive system. Most species of flatworms have no anus and a cavity with only one opening. While not all species do, many flatworm species use a mouth to eat. The only problem with no anus is that the stuff you don't digest has to go out the mouth when you're done. Other materials that need to be removed from the system can be excreted through specialized cells called flame
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 48
cells. Flame cells are the first appearance of excretory ducts in organisms. Flame Roundworms
They do not have specialized circulatory systems like annelids. Nematodes are round and have bilateral symmetry (both halves look the same). They also have special muscles that move down the length of that entire round body. Annelids (segmented worms) are different in that their muscles just work in each segment. Nematodes act like predators, hunting down other creatures. They are parasites, surviving at the expense of a host. The best example of nematodes as parasites is a disease called Trichinosis. Some are also herbivores, eating plant material and algae. How do they get so many places? It helps that so many species of nematode are very small. You need a microscope to see most of them. Segmented worms
They are special. The whole segmentation thing is the big one. They actually have loads of body parts that are duplicated in each segment. If one segment is damaged, some annelids can go on living. They also have something called a closed circulatory system. It doesn't seem that amazing because you have one. However, as far as developed creatures, annelids were one of the first. They circulate nutrients and compounds through their segments using tubes. Other creatures with open systems just let everything move around on its own. Closed circulatory systems are more efficient. Mollusks Mollusks are soft-bodied animals usually with hard external shells. They are the second largest group of animals. One-shelled molluscs are called univalves. These animals feed by scraping their tonguelike structure on food. snails , the only land mollusks, are examples of univalves.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 49
A univalve Bivalves are mollusks whose bodies are enclosed in two shells. Clams ,oysters and mussels belong to this group. They survive through filter feeding. They allow water to pass hrough their gills to get food.
Cephalopods Cephalopods such as the squid,nautilus and octopus, have large and welldeveloped heads. Unlike other molusks,they move fast and are mainly predators.
Other group of mollusks are the tooth shells and chitons. Tooth shells are marine molluscs living party buried in the mud or sand. Chitons are slow-moving molluscs that feed on algae. They are the only molluscs that have sensory structures in their shells.
tooth shells
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
chitons
Page 50
Arthropods Arthropods all have exoskeletons. Exoskeletons are hard outer shells made of chitin. While you have an endoskeleton, a crab has a tough shell that protects it from the outside world. Next on the list are the arms and legs. They have jointed appendages. That's what the name arthropod means. jointed leg. Inside those joints and exoskeletons are muscles that help the organisms move. Not all exoskeletons are the same. While they may all have chitin, a shell created by the epidermis, crustaceans have an extra layer that is calcified. That calcification makes it much sturdier and much heavier. Arthropods also have very advanced sense organs. You are probably familiar with the faceted eyes of flies and antennae on insects. Those are great examples of how arthropods are prepared to interact with the world. They also have open circulatory systems. These systems circulate nutrients throughout the inside of that exoskeleton so the muscles receive all the energy needed to move quickly.
Arachnids Arachnid (class Arachnida), any member of the arthropod group that includes spiders, daddy longlegs, scorpions, and (in the subclass Acari) the mites and ticks, as well as lesser-known subgroups. Only a few species are of economic importance—for example, the mites and ticks, which transmit diseases to humans, other animals, and plants. An arachnids body has two divisions-cephalotorax and abdomen. The cephalothorax contains the mouthparts and chest part. It bears the legs of arachnids. Arachnids have four pair of legs. They do not have an antennae. Spiders are free-living arthropods. They feed mainly on insects. Among arachnids, only spiders have spinnerets through which silk is secreted. Spiders make silk webs to catch pray. Ticks are bloodsucking arthropods. They feed on the blood of reptiles, birds and mammals. Some ticks carry organisms that cause serious human diseases. Scorpions have two pincers, similar to those of lobsters. These pincers are used to catch prey. They also have stingers at the tip of their tails to paralyze or kill their prey. They mainly feed on spiders and insects.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 51
Arachnids Crustaceans Crustaceans include some edible arthropods such as lobsters, shrimps ad crabs. They are mostly aquatic but some are terrestrial. Crustaceans have two body divisions. Similar to those of arachnids. Five pairs of legs are attached to the cephalothorax. In some crustaceans, the first pair of legs act as pincers. Crustaceans have two pairs of sensory glands called antennae. Their heads usually possess a pair of compound eyes. The head and the body are commonly covered with a thick case called carapace.
Crustaceans Insects Grasshoppers, bees, butterflies, mosquitoes and an array of similar arthropods comprise the insect group. They are the most abundant and widespread among all animals. How are animals able to survive life on Earth? Insects live in almost every habitat except seas. They adapt to a wide range of environmental factors. They do not need much water. They are the only vertebrates that can fly. Their life span usually are usually short However, they multiply rapidly by laying numerous eggs. Insects are distinguished from other arthropods by having a single pair of antennae, three body segments, and three pairs of legs.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 52
An insect’s body The head possess the insect‘s mouth and eyes. The thorax is the middle segment where the legs are attached. In most cases, wings are also located in this division. Wings are outgrowths of the exoskeleton. The digestive and reproductive organs of insects are found in the abdomen. Grasshoppers and other insects that feed on plants have mandibles that move from side to side rather than up and down. Insects that feed on nectar sip their food through the use of proboscis. Honeybees have mouthparts suited for both sucking and chewing. Most insects undergo changes in their body structures as they develop into adult insects. This process is called metamorphosis. Activity Match the items in Column A with those in Column B. Write on the blank the letter of your answer. A B _____1. tube feet a. tapeworms _____2. metamorphosis b. echinoderms _____3. osculum c. insects _____4. stinging cells d. bivalves _____5. setae e. univalves _____6. spinnerets f. coelenterates _____7. oysters g. sponges _____8. snails h. segmented worms _____9. suckers and hooks i. arachnids _____10. carapace j. crustaceans Echinoderms (Echinodermata) are a group of marine invertebrates that includes star fish, sea lilies, feather stars, brittle stars, sea cucumbers and sea urchins. There are about 6000 species of echinoderms alive today. Most echinoderms are bottom-dwelling animals that exhibit a variety of feeding habits including filter feeding, scavenging and predation. Present-day echinoderms are free-moving, but they evolved from sessile ancestors. Echinoderms have an endoskeleton composed of calcareous ossicles. In sea stars and brittle stars, the ossicles articulate to form flexible structures. In sea urchins and sand dollars, the ossicles are fused together to form a rigid skeletal structure known as a test.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 53
Echinoderms exhibit a type of radial symmetry called pentamerous symmetry in which their body can be divided into five equal parts around a central axis. Echinoderms developed this symmetry after they had already diverged from their bilaterally symmetrical ancestors. For this reason, the radial symmetry in echinoderms does not imply they are closely related to other organisms with radial symmetry such as cnidarians. Classification Animals > Invertebrates > Echinoderms Echinoderms are divided into the following taxonomic groups: Sea stars and starfishes (Asteroidea) - There are about 1500 species of sea stars and starfishes alive today. Members of this group live on the seabed and are found in every ocean around the world, from the intertidal zone down to the abyssal zone. Feather stars and sea lilies (Crinoidea) - There area about 600 species of feather stars and sea lilies alive today. Members of this group live attached to the seafloor and have a mouth at the top of their body that is encircled by feeding apendages. Sand dollars and sea urchins (Echinoidea) - There are about 950 species of sand dollars and sea urchins alive today. Members of this group have a round, spiny shell-like structure know as a test. Sea cucumbers (Holothuroidea) - There are about 1300 species of sea cucumbers alive today. Members of this group have a long body that is covered with leathery skin. Basket stars, brittle stars and snake stars (Ophiuroidea) - There are about 2000 species of basket stars, brittlestars and snake stars alive today. Members of this group have five long, thin arms. Echinoderms exhibit a type of radial symmetry called pentamerous symmetry in which their body can be divided into five equal parts around a central axis. Echinoderms developed this symmetry after they had already diverged from their bilaterally symmetrical ancestors. For this reason, the radial symmetry in echinoderms does not imply they are closely related to other organisms with radial symmetry such as cnidarians.
LESSON 22: PROTECTING CORAL REEFS AND ENDANGERED ANIMALS Corals are marine animals that exist as small anemone like polyps. Typically, corals form colonies of many identical polyps. Certain types of algae live in the polyps. Corals get their color and most of their nutrients from these algae. Corals YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 54
secrete chemicals that form hard skeletons. Because they grow in groups their skeletons pile up by wave action, producing a massive stony formation called reef.
Coral reefs that exist today have gradually formed over the past 5,000 to 10,000 years. Tropical waters that are warm and clear, with a stable temperature and salt content are ideal for reef development. Importance of Coral Reefs Reefs support living corals and a great variety of other animal life and plant life. They serve as breeding grounds for fish. Some aquatic animals feed on the algae growing on the polyp‘s bodies. Humans also get many benefits from coral reefs. Communities near major coral reefs enjoy an abundance of fish and other seafoods. Coral reefs are also good tourist spots. They provide tge best sceneries for scuba diving and snorkelling. Some corals are used as gemstones. Fire corals are used in making jewelry. Anticancer drugs and painkillers have also been developed from coral reef inhabitants. Threats to Coral Reefs It is estimated that about 60% of the world‘s coral reefs are at risk. In Southeast Asia, 80% of reefs are considered endangered. How are these coral reefs destroyed? Some weather phenomena. Like El Niño, increase the temperature of the sea surface. The warm temperature causes the algae that live in the corals to produce toxins. The corals expel the algae to save themselves. However, as a result, the corals lose their color (bleaching) and starve to death. Human activities are the greatest threat to coral reefs. People use some fishing techniques that are harmful to coral reefs.
Dynamite fishing is an extremely destructive method of fishing.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 55
Some fisherman use cyanide fishing to catch aquarium fish.
Muro Ami is another fishing technique that destroys coral reefs. Anchors of ships thrown in the ocean also destroy corals. Collecting corals as souvenirs or decorations also contributes to their rapid disappearance. Water pollution is another threat to coral reefs.
Protecting and Saving Coral Reefs 1. Destructive ways of fishing should be banned by the government. 2. Do not buy souvenirs and aquarium accessories made out of real corals. 3. throw garbage properly. 4. Practice responsible diving. 5. Educate other people who are not aware of the importance of coral reefs. Endangered Animals Endangered animals are those whose populations are low enough to be at risk of becoming extinct.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 56
Below are some of the endangered animals in the world.
Bleeding heart pigeon
dwarf goby
In the 2000 International Union for Conservation of Nature and Natural Resources‘ Red List, the number of endangered species in the Philippines is 418 out of 52, 177 species we have. Some endangered animals in the Philippines include the Philippine eagle, Philippine tarsier, Philippine bleeding heart pigeon, Philippine mouse deer (pilandok), dwarf goby (Pandaka pygmae), tamaraw, Visayan spotted deer and dugong. One of the major causes why animals become endangered is habitat destruction. Deforestation, mining, and destructive fishing are only some of the activities that continue to threaten the wide variety of species on the planet. Pollution also leads to habitat destruction. Overpopulation and conversion of natural areas to residential, agricultural, and industrial areas also contribute to the rapid loss of the animals‘ natural homes. Over exploitation of animals is another threat. These are some suggestions we can do to protect and save endangered animals: 1. Protect the habitats of animals. 2. Do not buy fur coats and other materials that are obtained from endangered animals. 3. Plant trees. 4. Obey rules and regulations in parks and national protected areas. 5. Support and join organizations that advocate protection of wildlife. 6. Report to authorities people who illegally hunt animals. 7. Secure proper documentations and permit from the government if you have an exotic pet.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 57
LESSON 23: FOOD-MAKING PROCESS IN PLANTS Plants are called autotrophs because they make their own food. This process of making food is called photosynthesis. Animals are called heterotrophs because they depend on plants for food. Things plants need to make food Leaves of plants are green due to the presence of a pigment called chlorophyll. This pigment traps the energy coming from sunlight. Plants use this energy to make food. The covered leaves could not absorb air. Carbon dioxide is the gas that plants need for photosynthesis. It enters through tiny openings called stomata. The droplets of water indicate that leaves lost some water due to evaporation. This evaporation of water in plants is called transpiration. Water is another material that plants need to make their own food. They obtain water through their roots that are underground or on the surface. Water, together with other dissolved materials, is carried up to the stem. It then reaches the leaves. Tiny tubes in the leaves distribute water all throughout the leaf blade. Photosynthesis
Photosynthesis is the process by which plants use energy from the sun to make their own food. Through this process, they get energy for different life processes, such as growth, reproduction, and repair.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 58
Here are some of the things that happens during photosynthesis. 1. Roots absorb water from the soil. 2. Water is transported from the roots to the leaves. 3. Chlorophyll captures energy from the sun. this energy is used to split water into hydrogen and oxygen. 4. Oxygen and moisture are released into the air. 5. Carbon dioxide enters the leaves through stomata. It then combines with hydrogen (result of the splitting of water) to make food in the form of sugar. 6. Sugar is transported from the leaves to other plant parts. Sugar is the food that plants produce. Because sugar dissolves in water, plants convert it to starch, which is nonsoluble. Starch is stored in plant body parts, such as in roots and stems. Test Yourself A. Identify what is described in each item below. ___________________ 1. Where oxygen escapes from the leaves. ___________________ 2. The green pigment of plants. ___________________ 3. The gas that plants absorb. ___________________ 4. The process by which plants make their own food. ___________________ 5. The stored food in plants. B. Arrange the steps in photosynthesis below by writing the numbers 1 to 6 on the blanks. ____ Oxygen and moisture are released. ____ Carbon dioxide enters the leaves and combines with hydrogen to form sugar. ____ The roots absorb water and minerals to the different parts of the plant. ____ Water is transported from the roots to the leaves. ____ The energy from the sun split water into hydrogen and oxygen. C. Answer the following questions: 1. What is photosynthesis? ___________________________________________________________________ ___________________________________________________________________ 2. What is the role of sunlight in photosynthesis? ___________________________________________________________________ ___________________________________________________________________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 59
LESSON 24: CLASSIFICATION OF PLANTS There are more than 260,000 species of plants on Earth. They range in size from small mosses to giant sequoias. To make the study of plants easier, scientist classify them into groups. Bryophytes Bryophytes are a wide collection of thousands of species. Mosses, liverworts and hornworts belong to this group. What are common to these plants? Bryophytes are generally small plants. They do not grow tall. They are non-vascular plants. This means that they do not have vascular or transporting tissues that carry food, water, and dissolved substances through their bodies. They do not have true roots. Instead they have rhizoids, which absorb water directly from the surface they grow on.
Figure 6.2 Bryopyhtes Tracheophytes Plants such as the santan,eggplant and mango tree are called tracheophytes.They are vascular plants.They have vasculaaar tissues that distribute food,water and dissolved minerals throughout their bodies.There are two kinds of vascular tissues. Xylem carries water and minerals from the roots to the stems and leaves. The phloem delivers the manufactured food from the leaves to the entire body of the plant. Tracheophytes are the most dominant plants they include trees, flowering plants, and non-flowering plants. They are further classified into spore-producing and seedproducing plants.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 60
Figure 6.3 Tracheopyhtes Spore-producing Plants Spore-producing plants are vascular plants that reproduce through spores. Are you familiar with ferns? They have spore cases called sori (singular:sorus) on the underside of their leaves. These cases appear as brown spots. When sori dry out, they break open. Spores are then carried by the wind,or they fall on the ground. Under good conditions, spores germinate and grow into ferns. Horsetails and club mosses are also spore-bearing plants.
Figure 6.4 Spores on the underside of a fern leaf Seed-producing plants Most plants around us reproduce by menas of seeds. Pines, bananas, grasses and flowering plants are examples of seed-producing plants. Most seedproducing plants have seeds enclosed in an ovary,which develops into a fruit.Few have exposed seeds.
Figure 6.5 Seed-producing plants YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 61
1. Cone-bearing plants Flowerless seed-bearing plants are called gymnosperms. it is derived from the word ‗‘gymno‘‘, which means ‗‘naked‘‘. and sperma, which means ―seed‖. The seeds of gymnosperms are not inside their fruits. They are exposed and are usually located in a cone. This is why gymnosperms are called cone-bearing plants. Conifers are common cone-bearing plants. They have cones instead of flowers. Seeds are exclusive to female cones. Female cones bear the ovules in conifers. Male cones carry the pollen. Pollination in conifers depends on wind. When pollen is blown into female cones, fertilization occurs and seeds are produced. Examples of conifers are pines, firs, spruces, junifers, and cedars. They all have needle-like leaves. They maintain their green color all year long. This is why they are also called evergreens.
Figure 6.6 Conifers 2. Flowering plants Flowering plants are the dominant forms of plant life. Many of them are sources of food, raw materials, natural products. They are also called angiosperms. The seed of angiosperms develop in the ovary of a flower. Can you recall the parts of a flower? The development of seeds in the ovary, which later becomes the fruit, is a characteristic common among angiosperms. Angiosperms are grouped based on the number of seed leaves or cotyledons in the germinating seed. Monocotyledons or monocots have one seed leaf. They are mostly herbaceous or without woody stems. Lilies ,orchids, grasses and palms are
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 62
monocots. Dicotyledons or dicots have two seed leaves. Example of dicots are the narra tree, cabbage and mongo. Flowering plants may either be further classified according to the length of time within which they produce seeds, bear flowers and live. Annuals produce seeds and bear flowers in the same year. They die when cold temperatures set in. Beans, petunias, and tomatoes are annuals. Biennials such as carrots, live for two years. They grow leaves in the frist year. In the second year, they produce flowers and die. Perennials, which include shrubs and trees, live for more than 3years.They produce flowers and seeds over the years.
Figure 6.7 Flowering plants Activity Identify each plant as bryophyte or tracheopyhte. ____________1.moss ____________2. Sampaguita ____________3. Spruce ____________4. Hornwort ____________5. Mongo
`
____________6. liverwort ____________7.rose ____________8. avocado ____________9. pine ____________10.oregano
B. Identify each plant as gymnosperm or angiosperm. ___________1.ginkgo ___________2. Dahlia ___________3. Patola
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
___________11. fir ___________12. coconut ___________13. Bougainvillea
Page 63
C. Answer the following questions: 1. Why do bryophytes not grow tall? _______________________________________________________________ 2. What are the functions of the xylem and phloem? ____________________________________________________________________ _____________________________________________________ 3.What are the differences between monocots and dicots? ____________________________________________________________________ ____________________________________________________
LESSON 25: ADAPTATION OF PLANTS Plants cannot run away from enemies like enemies can. They cannot burrow under the ground to avid too much exposure from the sun. However they have their own adaptations to protect themselves and survive despite unfavourable environmental conditions. Protective adaptations Some plants, such as roses and blackberries, have thorns. Thorns are specialized stems. Some plants such as bougainvillea and pomelo, have spines. Spines are modified leaves. Other plants have prickles or hairs around their stems. Grazing animals are not attracted to eating plants with such pointed structures.
Fig. 6.8 Plants with thorns and spines
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 64
There are plants that can cause skin irritation because of their hairy or sharp leaf blades. Insects avoid eating the ramie plant and nipa palm because they have this structure.
Figure 6.9 a nipa palm The pineapple plant also has a sharp leaf blades that can cut skin. These make the pineapple unfavourable to eat or touch.
Figure 6.10 The sharp leaf blades of a pineapple Other plants have an unpleasant smell. Citrus plants secrete a sticky substance that produces a strong and unpleasant odor. This odor drives animals away.
Figure 6.11Citrus plants
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 65
Reproductive Adaptations Plants also need to adapt for successful reproduction. Some plants bear colorful flowers. The colorful petals and sweet smell of flowers attract insect and birds to rest on them. Some flowers produce nectar that attracts insects such as bees and butterflies. These insects help the plants in pollination.
Figure 6.12 Plants with colorful flowers Plants also have adaptations for successful seed dispersal. Some fruits develop fleshy fruits that attract humans and animals. As the fruits are eaten, the seeds are exposed and scattered.
Figure 6.13 Fleshy fruits
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 66
Some fruits , such as beans and other legumes,split open when they ripen and dry. When the seeds drop to the ground ,they may be scattered by animals. They may also be scattered by flowing water. Figure 6.14 A dried bean pod split open
Some seeds have hairlike or featherlike structures. They may stick to the fur or feathers of animals or get carried by the wind. The narra fruit may be carried by the wind over long distances because of its winglike structure. Figure 6.15 The winglike structure of the narra fruit Adapatations to Habitat Have you seen trees that turn their leaves into different colors when seasons change? Deciduous trees such as maples and oaks, shed their leaves to reduce water loss. They then conduct photosynthesis in their stems.
Figure 6.16 Deciduous trees Grasslands have a windy and dry condition .Many prairie grasses have soft stems that bend with the direction of the blowing wind, thus keeping them from breaking. They also have narrow leaves. This structure helps lessen water loss.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 67
Figure 6.17 Prairie gasses Some desert plants are succulents. They store water in their stems or leaves. Cacti store water in their stems. Their spines are their leaves. Spines protect the cacti from hervibores.
Figure 6.18 Cacti Plants in rainforest develop drip tips and waxy surfaces. These allow excess water to run off. Some rainforest plants, like bromeliads, climb on other plants to reach sunlight.
Figure 6.19 The drip tips on the leaves of a forest plant. Some aquatic plants have air spaces in their stems to hold them up in water. They have tough stems and leaves to withstand weather and water movement. Plants that do not float on water have their stomata on the upper surface of their leaves so that gas exchange can take place.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 68
Figure 6.20 A water lily
Some plants have narrow leaves. Pine trees have needlelike leaves. This structure allows them to less water loss. They also have flexible branches to drop off too much snow and prevent branches from breaking due to too much weight.
Figure 6.21 Pine tree Activity A. Give two examples of plants for each structural adaptation indicated in the table below. Structural Adaptation Examples of Plant How do These Structure Help Them Survive? Thorns Spines Bad odor Needlelike leaves Colorful petals
B. Answer the following questions 1. Why do plants need to adapt to their environment?
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 69
____________________________________________________________ 2. How do deciduous trees reduce water loss? ____________________________________________________________ 3. How do desert plants survive in a dry habitat
LESSON 26: PLANTS AND THEIR USES Plants are major sources of food. Fruits, Vegetables And Grains Fruits are thee seed-bearing parts of a flowering plant. Many fruits taste sweet and are juicy. Most seeds, such as mongo and peas, are edible. Green leafy vegetables, such as malunggay, sweet potatao tops (talbos ng kamote), kangkong, and cabbage are nutritious foods. Fruits and vegetables are good sources of fiber necessary for a healthy digestive system. Grains are the fruits of certain grasses. These are sources of carbohydrates and fiber. Common grains include rice, wheat, oat, and barley.
Figure 6.22. fruits,vegetables and grains Rootcrops Carrots, yam and ubi or uber are common root crops. They provide our body with essential nutrients. For example carrots have carotenoids, which are known to fight cancer.
Figure 6.23.Root crops YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 70
Flowers some flowers are also edible. They are tasty and nutritious. The flowers of squash are used in some Filipino viands.
Figure 6.24The squash flower is edible Oils Plant oils such as cocnut oil, sesame oil, and olive oil are widely used in cooking.
Figure 6.25 Oils from plants Plants Supply Oxygen And Purify The Air Plants give off oxygen as they manufacture food. Oxygen is used by animals during respiration. Plants also purify the air we breath by absorbing the air‘s carbon dioxide content. Plants are sources of medicines
SAMBONG
GUAVA
GARLIC
Since ancient times, plants have been sources of medicines. The Philippine is rich with herbal medicines. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 71
Garlic is one of the widely used herbal plants. Its medicinal properties have been proven for a long time. It is known as a natural antibiotic. It also helps to lower the level of bad cholesterols in the body. Gumamela is another medicinal plant commonly used in the Philippines. Its roots, leaves, and flowers are popularly utilized to remedy coughs. Sambong is a famous medicinal plant. Sambong aids in kidney disorders. Powdered sambong leaves are available in tablet form Guava leaves is for cleaning and disinfecting wounds. Akapulko is an erect shrubby legume whose seed are used against intestinal parasitism. It also has an antifungal property that can act against some skin infections. Oregano is one of the most common medicinal plants. It is popular for its strong aroma. The juice of oregano leaves is proven effective against chronic coughs and other respiratory ailments. Ampalaya (bitter melon) is a vine that is widely known for its bitter taste due to the presence of a substance called mormodicin. Ampalaya is also a good remedy for diabetes and its juice is also good for patients who are suffering from cough, fever and diarrhea. Lagundi is commercially known as an effective treatment for coughs, colds and flu. It is available in syrup and tablet forms. Its natural preparation involves the extraction of its juice from leaves, roots and stems. Niyog-niyogan’ leaves (Chinese honeysuckles) are commonly used to cure muscle pains by placing to to the painful area. The dried seed of niyog-nioyagan are also effective for deworming. Tsaang gubat (wild tea) is a shrub whose leaves are boiled for treating diarrhea. Its tea can also be used as a mouth gargle. Pansit-pansitan (peperomia) is a small shrub growing along streets, sidewalks another open spaces. Its leaves and soft stem can be eaten raw and be put in fresh salads. Though medicinal plants are proven effective, it is important to consult a physician on how to prepare these medicinal plants properly. Plants prevent erosion and floods The roots of plants hold the soil in place. They absoyb large amounts of rainwater and prevent floos. Without enough plants wind and water erode the soil. Plants Beautify Surroundings Plants add beauty to our surroundings. Colourful flowers give life to a dull scenery. Ornamental plants are usually grown in gardens because of their attractive color and appearance like cadena de amor, santan, bougainvillea, and lantana in the Philippines.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 72
Figure 6.29.Some Ornamental Plants Other Uses Of Plants Plants provide shelter for many animals. Many kinds of fibers used in making clothes come from plants. Cotton is a common fiber-producing plant. Fibers from pineapple are made into barong, filipiniana clothes and kimonos. Plants also provide materials for building human shelter. Molave, kamagong, narra and yakal are good sources of lumber. Cogon and nipa re used on huts.
Figure 6.30 Plants are used to make furniture Activity Write names of four plants for each use below.
As food
Uses of plants As clothing As medicines As housing As ornament materials materials
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 73
LESSON 27: CARING FOR AND CONSERVING PLANTS Almost all forms of life on Earth depend on plants. Plants provide food and oxygen. Without plants, there would be no life on Earth. Forest are important habitats. They are home to numerous animals and other organisms. However forests are rapidly disappearing. Deforestation refers to the clearing of forests. Various human activities have resulted in deforestation. Many forests and other natural habitats are transformed into human settlements. Forest are cleared to provide lands on which to build homes. They are also cleared for agricultural and industrial purposes. Trees are cut to obtain wood and other materials. However, excessive cutting of trees has left many forests barren.
Figure 6.31 Kaingin is one cause of deforestation Kaingin (slash-and-burn farming method of clearing an area) is another human activity that has led to human activity that has led to massive disappearance of forests. Forests are also cleared to give way to mining operations. Extraction of gold, copper, diamonds and other metals and gemstones also leads to pollution that degrades the condition of forests. Chemicals such as mercury and sulphuric acid are unearthed in mining operations. These chemicals seep into the ground and affect the health of trees. Everyone should contribute to the conservation of plants. Here are some ways of caring for plants. 1. Provide the needs of plants .To grow healthy, plants need sunlight, water, and minerals. Water plants every day. Fertilize the soil. Make sure plants have enough access to sunlight. Put a fence around a young plants to protect them from grazing animals. 2. Do not cut down young trees. Replace trees that have been cut down by planting new trees. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 74
3. Practice the principle of ‗‘reuse, reduce and recycle‘‘. Overconsumption of plant products leads to more cutting of trees. 4. Avoid buying products that are made of materials from rare types of trees. 5. Report illegal logging activities. Be involved in organizations that promote conservation of forests. 6. Share information about the problems related to the disappearance of forests and the efforts that the government, various organizations and concerned individuals are exerting toward forest conservation
UNIT 3: CHAPTER 7 MATTER LESSON 28: MATTER AND ITS PROPERTIES Matter exists in different forms and states. There two different properties: general properties and special properties. General Properties General properties are those that characterize every phase of matter. Solids, liquids and gases all have these general properties. General properties include mass, weight, volume and density. Matter has Mass and Weight Mass is the amount of matter in an object. Mass tells you how much matter there is in an object. It is usually expressed in grams (g) or kilograms (kg). Matter also possesses weight. Weight is the pull of gravity on an object. It indicates heaviness or lightness of an object. It is expressed in newtons. Mass 1.0 kg of potatoes
Weight 2.0 kg of potatoes
9.8 newtons of potatoes
19.6 newtons of potatoes
Matter has Volume Volume is the space that matter occupies. The volume of a rectangular object is determined by multiplying its dimensions, namely, length, width, and height. Units of volume include cubic centimetre (cm 3) and cubic meter (m3).
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 75
Figure 7.3 The volume of this rectangular block of wood is 104 cm.Âł Through the water-displacement method, the volume of a solid that have an irregular shape can be determined. In this method, an irregular solid is immersed in water. The increase In water level is subtracted from the original level. The difference is the volume of the irregularly-shaped solid. Matter has Density Density tells how much matter is present in a given unit of volume. It is determined by dividing the mass of an object by its volume.
Mass = 720 g Volume – 180 cm3
density = mass/ volume density = 720 g / 180 cm3 density = 4 g/cm3
Special Properties of Matter The special properties of a type of matter depend on its internal structures, special properties differ from one material to another. Some materials have he ability to allow electricity or heat to pass through them. They are called conductors. Metallic objects are good conductors. they also exhibit luster. Light bounces off as it strikes on a metallic surface. Some widely used metallic elements are gold, silver, aluminium, tin, and copper. They are mostly in wires, jewelry, kitchenware, some computer parts and steel.
Figure 7.5 Conductors Objects do not readily permit electricity or heat to flow through them are called insulators. Paper, glass, wood and rubber are insulators. They are commonly used in pot holdrs, windows wire coverings, gloves and furniture.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 76
The behaviour of a material in relation to light is also classified as a special property. Based on this property,materials can be transparent, translucent or opaque. Some materials allow light to pass through them completely. These materials are known as transparent objects. These objects are often used in windows, reading glasses, container, laporatory apparatus, and screens. Materials that allow only some amount of light to penetrate and pass through them are called translucent objects. Examples of translucent objects are stained glass and lampshades. Some objects completely block light rays. These are called opaque objects. Examples include wood, leather and rubber.
Figure 7.7 a. transparent object,
b. translucent object, and c an opaque object.
Some materials exhibit attraction to magnets. This is referred to as magnetic property. Most metals are magnetic. Metal spoons, coins, and refrigerators are examples of magnetic objects.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 77
Activity A. Identify the term that each statement describes. ______________1. It is the total amount of space that an object occupies. ______________2. This is the ability of some materials to reflect light. ______________3. It is the amount of matter in an object. ______________4. These are materials that allow light to completely pass through them. ______________5. It is the relationship between mass and volume. B. Identify the special property of matter that each labelled object shows.
1. diamond_________________
2. Reading glass____________________
3. casserole_________________
4. Copper______________________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 78
LESSON 29: MIXTURES Target: Differentiate homogeneous from heterogeneous mixtures Give examples of homogeneous from heterogeneous mixtures. Make samples of homogeneous and heterogeneous mixtures
A mixture is composed of two or more different materials that are physically combined.The materials are simply mixed; therefore, no new substance is formed. Each substance in a mixture retains its properties. Mixtures can be generally classified into two: heterogeneous and homogenous mixtures. Heterogeneous Mixtures In a halo-halo mixture, you can still identify the ingredients that are mixed together. Notice that the substances are not spread out evenly. This type of mixture is heterogeneous. Other examples are mixtures of pebbles and sand, rice grains and ipa, and soil and stones. A heterogeneous mixture may also be a combination of a solid and a liquid. Peebles and water in an aquarium may be cited as an example.
Figure 7.9 The mixture of pebbles and water in an aquarium Homogeneous Mixtures Some mixtures are composed of substances that are evenly distributed. These mixtures are homogeneous. Water when mixed with other substances in liquid form is a good example of a homogeneous mixture. An alcohol called ethanol is mixed with water to make homogeneous alcohol beverages. Air is a mixture of gases, including nitrogen, carbon dioxide, oxygen and water vapor. A homogeneous mixture can also be a YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 79
mixture of solid in liquid, such as powdered milk in water. It can also be a mixture of gas in liquid,such as carbon dioxide in soft drink.
Figure 7.10 Samples of homogeneous mixtures: milk and soft drink
Test Yourself Classify each of the given mixtures. Write HT on the blank if the mixture is heterogeneous and HM if it is homogeneous. _______1. mixture of paper clips and thumbtacks _______2. stirred mixture of vinegar and salt _______3. mixture of soil and water _______4. sugar stirred in ketchup _______5. mixture of ink and water
LESSON 30: KINDS OF MIXTURES Below are some pictures of milk, coffee and muddy water. How does one differ from the others? Mixtures can be further classified into three kinds: solutions, suspensions and colloids.
Solutions Orange juice is an example of a solution. A solution is a mixture of two or more substances having particles that are so tiny that they are invisible to the naked eye. These tiny particles are evenly distributed, resulting in a homogeneous mixture. What happens when you put sugar in water? Does the sugar dissolve easily? Putting the sugar crystals renders the water sweet. You cannot see the sugar crystals but you can taste them. This is because the sugar crystals remain as sugar
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 80
but dissolve and distribute evenly in the water. The sugar crystals retain their properties. In a solution, the substance that dissolves another substance is called the solvent. It is often a liquid. The substance that is dissolved is called the solute. In a sugar-water solution, water is the solvent and sugar is the solute. If the amount of solvent is much greater than the solute, the solution is described as dilute. If there is a large amountof solute in the solvent, the solution is said to be concentrated. Make sure you read the label of the juice drink or mouthwash that you buy. If it is concentrated, it means you need to add water to it.
Figure 7.11 Concentrated juice drinks and mouthwash solutions What do you think will happen if you put some vinegar into water? What results is an example of a liquid solution. The vinegar dissolves in water. Substances that dissolve in a solvent are known as soluble substances. Those that do not dissolve are called insoluble substances. A liquid dissolving in another liquid is described as miscible. Vinegar is miscible in water. Oil on the other hand, is immiscible in water for it does not mix with water. Solutions can be combinations of solid materials. A uniform mixture of zinc and copper forms brass. Bronze is made from copper and tin. Factors That Affect Solubility Solubility is a measure of a solute‘s ability to be dissolved in a specific solvent. It is affected by the following factors: 1. Stirring Prepare two glasses with equal amounts of water.Add one tablespoon of rock salt to both glasses. Stir one of the solutions. What do you notice? In which glass do the salt crystals dissolve quickly? Stirring speeds up the process of dissolving because it mechanically breaks down and scatters the solute particles.
Figure 7.12 Stirring results in faster dissolution
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 81
2. Temperature Get two glasses. Put hot water in one glass and tap water in the other. Make sure that the amounts og water in both glasses are equal. Add one tablespoon of coffee powder to each glass. Do not stir. Observe what happens. In which glass does the coffee powder dissolve faster? A rise in temperature increases the, movement of particles of the solvent. This increases the rate of dissolution.
Figure 7. 13. A warmer solvent dissolves the solute faster. 3. Size of Particles Prepare two glasses with equal amounts of water. Put an alum rock (tawas) in one glass and alum powder in the other. Does the solute in both glasses disappear at the same rate? The Alum Rock dissolves more slowly because a smaller surface area is exposed to the solvent. On the other hand, alum powder dissolves faster because the total surface area of all the powder particles exposed to the solvent is greater.
4. Viscosity of Fluids Viscosity is the resistance of fluids to flow. To understand it better, get two drinking glasses. Fill one glass of water and the other one with honey. Using a spoon, scoop a tablespoonful of water and pour it gently to its container. Do the same with the honey. Which liquid is viscous or hard to pour? A viscous liquid, such as honey, dissolves solutes more slowly.
Suspensions A mixture of water and flour has a cloudy appearance. Some particles of the flour remain suspended in the water. However, after leaving the mixture undisturbed for some time, bigger particles slowly settle at the bottom. This kind of mixture is called a suspension. A suspension is a mixture of two or more substances where the particles are not evenly distributed throughout the mixture. Some particles are large enough to be seen and they settle at the bottom. The smaller particles remain suspended, causing the mixture to appear cloudy.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 82
Figure 7.16 Examples of suspension Colloids A colloid is another kind of mixture. Colloids have particles that remain suspended throughout the mixture. Colloidal particles are larger than the particles in solutions but smaller than the particles in suspensions. Paint is an example of a colloid. Other examples include glue and whipped cream.
Figure 7.17 Examples of colloids To determine if a mixture is a colloid, one can check if it will exhibit the Tyndall effect. Particles in a colloid scatter light producing a beam. Such scattering of light is called the Tyndall effect. A light beam is not produced when light passes through a solution. Activity1 Identify each mixture as a solution, colloid, or suspension. Write S, C, or SP to indicate solution, colloid or suspension, respectively. ______1. milk ______2. chalk in water ______3. gelatin ______4. seawater ______5.fog
_____6. paste _____7. yogurt _____8.fruit juice _____9.all-purpose cream _____10. air
B. Answer the following questions: 1. How does stirring affect solubility? ___________________________________________________________________ 2. How do the three kinds of mixtures differ? ___________________________________________________________________ 3. Why does a colloid scatter light? ___________________________________________________________________ YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 83
Lesson 31: WAYS OF SEPARATING MIXTURES Target: To identify ways of separating the components of mixtures Get Ready What is the woman below doing? What mixture is involved in the process? Aside from winnowing, do you know other ways of separating rice grains from chaff? You have learned that the particles in a mixture vary in size and other characteristics. Different ways can be done to separate the components of mixtures. Picking out A mechado dish is a mixture of potatoes, meat, carrots, peas and other ingredients. You may pick out only the meat from the dish. Picking is the simplest way of separating mixtures. Sieving A sieve is a tool to separate desired substance from unwanted ones using a mesh or net. You use a strainer to separate the noodles from the water when you cook instant pancit canton. Notice that the construction workers use framed nets to separate sand from stones. Decanting Decanting is done by carefully pouring the floating liquid of a mixture from a container, leaving the sediments or denser liquid at the bottom. Decanting is usually use to separate oil from water. Because water is denser than oil, it stays at the bottom as you pour out the oil. Filtering Filtering is a physical way to separate solids from liquids or gases. It uses a filter medium, such as cloth or filter paper through which the fluid can pass, retaining the solids. In sieving, the particles separated are bigger than those in filtering. Filtering devices attached to faucets are used in many homes to filter out solid impurities. Evaporating Suppose you have a mixture of water and juice powder. How will you separate the substances to have only juice powder in the container? Some dissolved substances in water can be separated by allowing to evaporate. Evaporating does not necessarily require boiling. We can recover dissolved substances by plain the solution under the sun . Boiling, on the other hand, makes the separation process faster. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 84
Using Magnets When a mixture is composed of some metals, the metallic substances can be separates using a magnet. Activity Identify a good way of separating the components of each of the following mixtures: _______________1. Fruit salad _______________2. Mixture of rice grains and hulls _______________3. Mixture of stones and water _______________4. Mixture of water and oil _______________5. Mixture of detergent powder and water _______________6. Mixture of peas,nuts and beans _______________7. Mixture if sand and iron _______________8. Mixture of alcohol and water _______________9.mixture of noodles and soup _______________10. Mixture of noodles and soup Go Beyond Did you know that only 1% of the Earth‘s water is available for humans to drink? Two percent is estimated to be locked in ice and the rest belongs to the seas and oceans. According to BBC, Sana‘a in Yemen is the global capital of water shortage. People there fight one another to get water. Experts are now looking at tapping sea water for human consumption. Seawater is a mixture of various materials and microscopic living things that are unhealthy for humans. How can experts make seawater healthy for us? What can you do to save water?
LESSON 32: STATIC ELECTRICITY Target: To describe static electricity To explain how static electricity is produced A boy rubs an inflated balloon against a carpet. He tries to place the balloon on a wall. What do you think will happen? Draw your prediction in the box. Then compare your prediction with those of your classmates.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 85
Electricity runs the trains in Metro Manila. It also powers the roller coasters in amusement parks. Many of the products of technology today need to be plugged in to a source of electric current in order to work. However, a form of electricity called static electricity cannot turn on a television set or power an electric fan. Static electricity is the build up of electric charges on the surface of objects. You learned that matter is made up of atoms. Atoms are composed of smaller particles called electrons, protons and neutrons.
Figure 8.1 Atomic model Look at Figure 8.1Electrons are the tiny particles spinning around the dense center called nucleus. Electrons are negatively charged particles. At the nucleus, two kinds of particles are found-protons and neutrons. Protons are positively charged, while neutrons have no charge. A neutral atom has the same number of electrons and protons. These particles cancel each other‘s charge, giving the atom zero charge or no charge at all. Based on the atomic model, which particle can be pulled out easily from the atom? Rubbing two objects together permits electrons to transfer from one object to another. This makes the objects electrically charged. An object that has lost electrons is positively charged. A positively charged atom has more protons than electrons. On the other hand, an object that has acquired electrons is negatively charged. The electric charge that is formed on an object‘s surface when electrons transfer is a form of static electricity. When you comb your hair several times and place the comb near small pieces of paper, paper will stick to the comb. Rubbing the comb against your hair makes the comb negatively charged. When the comb is brought near the pieces of paper, the electrons in the paper move away from the comb. This leaves the part of the paper near the comb positively charged. The attraction between opposite charges makes paper cling to the comb.
Figure 8.2 Running a comb through the hair gives the comb static electricity. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 86
On a page 280, you were asked what would happen if an inflated balloon that had been rubbed against a carpet was placed near a wall. When the balloon was rubbed, it gained electrons, making it electrically charged. As an electrically charged balloon is placed near the wall (a neutral surface), the electrons in the wall move away. The positive charge on the surface of the wall attracts the balloon stick to it, as shown Figure 8.3
Figure 8.3. Static electricity in a balloon makes it stick to the wall. Activity A. Read each statement below. Write true on the blank if the statement is correct. Write false if it is correct. ______1. Protons and electrons are found in the nucleus. ______2. Rubbing causes electrons to transfer from one object to another. ______3. Objects with like charges attract each other. ______4. An atom has no charge if the number of electrons is equal to the number of protons. ______5. Neutrons spin around the nucleus of an atom. B. Answer the following questions: 1. What is static electricity? _____________________________________________________________ 2. How is static electricity produced? _____________________________________________________________ 3. When do two objects attract each other? When do they repel each other? _____________________________________________________________ Go Beyond Research on Benjamin Franklin‘s experiment on lightning.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 87
Lesson 33: ELECTRIC CURRENT Targets
Define electric current Cite examples of conductors and insulators Identify the parts of simple electric circuit Construct a model of a simple electric circuit
Electric current is produced by flowing electric charges. It is the kind of electricity that runs your electrical appliances. It is produced when electrons flow through a material. Electric current is like a flowing river. It is characterized by a continuous and controlled flow of electrons. The direction of flow is from the negative terminal to the positive terminal. Metals allow electrons to flow easily through them. These materials are called conductors. Materials such as copper and aluminum, are good conductors of electricity. Materials that do not allow electrons to flow easily through them are called insulators. Insulators include wood, rubber, paper plastic and glass. Notice that electric wires are covered with insulators. This is to protect us from electric shock. Electric Circuit A path where current flows is called a circuit. When the electric current flows is called a circuit. When the electric current flows in a circuit, it can be transformed into other forms of energy such as light, heat, sound, and mechanical energy. A simple circuit has the following parts: a. The source supplies the electricity. Examples of sources are batteries and generators. b. The conductors are connecting wires that link the source to the electrical device. c. The load is the electrical device that uses the electricity to other forms of energy. It can be a radio, a bulb, or any other electrical device. d. The switch is the controlling device that opens and closes the circuit. For electricity to travel where we need it there must be a complete circuit. Parts should be properly connected. A complete circuit is like a circle. When you switch off an appliance, you create a gap in the circuit that has a break or gap is called an open circuit. Electrons do not flow in this kind of circuit.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 88
Figure 8.5 Open circuit On the other hand, electrons flow in a closed circuit. There is no gap in a closed circuit .Therefore, electrons can freely flow from the source to the load.
Figure 8.6. Closed circuit Activity A. Which of the following objects are conductors? enclose each of them in a box.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 89
B. Answer the following questions: 1. What is electric current? ___________________________________________________________ 2. How would you differentiate the following? a. conductors and insulators ___________________________________________________________ b. open circuits and closed circuits ___________________________________________________________
Lesson 34: KINDS OF CIRCUITS Targets:  Differentiate series from parallel circuits  Construct circuits with series and parallel connections Series Circuits Why is it that when one bulb in a string of Christmas light bulb gets busted, the remaining bulbs do not work anymore? This is because Christmas light bulbs are often connected in a series. In a series circuit, electrons flow through a single path. The flow of electricity starts at the negative terminal of the source, passes through a series of electrical devices, and then to the positive terminal.
Figure 8.7 Series circuit If one of the bulbs in a series circuit is removed, the remaining bulbs will no longer work. Remember that electricity flows in only one path in a series circuit. The flow of electrons is cut off when one of the bulbs is missing or when it is busted.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 90
Because there is only one path for the electric current, all electrical devices receives the same amount of electricity. Each bulb is as bright as the other bulbs provided their assistance to the flow of current is the same. Parallel Circuits Most of the appliances and other electrical devices in our homes are connected in a parallel circuit. In a parallel circuit, the electrical current travels through wires in more than one path. Each electric device receives electricity through a separate path. Look at the Figure 8.8If you remove one bulb, will the remaining bulb still work?
Figure 8.8 Parallel circuit In the circuit above, if one bulb is taken out, the electric current can still flow. Therefore the remaining bulb will still work. All devices in a parallel circuit are connected across the same voltage. The electricity moves across the wire because of a certain ‗‘push‘‘ exerted by the source. This push is called the voltage. The following is a schematic diagram of an open series circuit.
bulb wire battery
switch
Figure 8.9 Schematic diagram of an open series circuit
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 91
Activity A. Write S on the blank if the statement refers to a series circuit, P if it refers to a parallel circuit and SP if it refers to both. ______1. Electricity is cut off when one electrical device gets burned. ______2. Electricity can only flow when the circuit is closed. ______3. Electric current travels in more than one path. ______4.Electrical appliances receive the same amount of electric current. ______5. Loads lie along a single path of electric current. A. Draw diagrams of the following circuits using the schematic symbols: 1. parallel connection of two light bulbs, two switches, and a battery
2. parallel connection of four light bulbs, one switch, and a battery
3. series connection of three light bulbs, one switch, and a battery.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 92
4. series connection of four light bulbs, two switches and a battery
Go Beyond Electric circuits allow electricity to flow so as to supply every load with the right amount of power it needs to operate. However, there are instances when there is too much electricity in the circuit. An electrical overload can occur when several electric cords are connected to a single electrical outlet. Such connection is called an ‗‘octopus connection‘ ‘This is dangerous because an electrical overload can cause overheating of elements and eventually fire.
LESSON 35: GENERATION OF ELECTRICITY Targets Identify the sources of electricity Explain how electricity reaches our homes Do you have an idea where electricity comes from? Draw inside the box the different sources of electricity that are familiar to you. Electricity is produced as a result of either chemical reactions or movement. Let us study some sources of electricity. Dry Cells Batteries such as those that make your remote control work are also known as dry cells.
Figure 8.10 Dry cells YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 93
A dry cell is a device that produces electricity through chemical reactions. It has a chemical paste inside that produces electricity. It is commonly used in flashlights, audio recorders, remote controls, and handheld gaming devices.
Figure 8.11 Parts of a dry cell Wet Cells Have you seen a car battery? A car battery is an example of a wet cell. A wet cell is filled with chemicals known as liquid electrolytes. Electricity is produced as a result of chemical reactions between an electrolyte (like sulfuric acid solution) and metal plates such as lead and lead oxide.
Figure 8.12 Car batteries are wet cells. Generators Electricity from batteries is not enough to power your refrigerator and make two or more home appliances function simultaneously. To make them work, a great amount of electricity should be supplied by machines called generators. A generator is a machine that converts energy of motion into electrical energy. It has coils of wires and a strong magnetic force inside. The coils of wire are attached to a turbine. Falling water, wind, or steam makes the turbine spin. The spinning of the turbine makes the generator work.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 94
Figure8.13 Equipment involved in generating and transmitting power to homes How does electricity reach our homes? Electricity generated from power plants called power producers is transmitted through transmission lines. Electricity reaches a substation where the electric voltage is decreased by step-down transformers. From the substation, electricity is distributed to our homes through the distribution lines. When electricity reaches our homes, it can then be used to make our electrical appliances work. Those who use electricity for different purposes are called power consumers.
Figure 8.14 Transmission of electricity Activity A. Label the parts of a dry cell. 1.__________ 2.__________ 3.__________ 4.__________ 5.__________ 6.__________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 95
Go beyond Houses and commercial buildings that use electricity are charged by their electrical provider for their electric consumption every month. How is the electric consumption measured? Electrical providers use electrical meters to determine the amount of electrical energy used. Electrical meters are attached outside the buildings. They are calibrated in kilowatt-hours. Electric meter readers take readings of the meters periodically. The electrical provides computes the electric consumption from these readings. It then charges the costumers for the amount of electricity used.
Electric meter
LESSON 36: ELECTRICITY AND MAGNETISM  Describe how electromagnets work  Identify factors that affect the strength of an electromagnet Using a galvanometer, a bar magnet, and a long piece of wire, follow the instructions below. 1. Attach the ends of the wire to the galvanometer. 2. Wind the wire into three-equally sized loops. 3. Plunge the magnet inside the wire loops. 4. Move the magnet in and out. Observe the galvanometer reading. 5. Repeat steps 2 to 4 with an increased number of loops. Commonly, we think of a magnet as a piece of stone that attracts a metal to itself. Magnets come indifferent shapes. There are horseshoe magnets, bar magnets, and ring magnets. Another kind of magnet exists. This is the electromagnet. An electromagnet is a magnet that needs electricity to operate. A simple electromagnet can be made using a dry cell, a nail and a piece of wire. Look at Figure 8.15.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 96
Figure 8.15. A simple electromagnet The iron nail acts like a magnet when electricity passes through the coil of wire around it. Unlike ordinary magnets, electromagnets can be turned on and off. This is because when there is no electricity flowing through the wire, an electromagnet loses its ability to attract metallic objects. Electromagnets are used in buzzers, doorbells and telephones.
Figure 8.16. Some objects with electromagnets Factors That Affect Electromagnetic Strength The strength of an electromagnet is determined is determined by the following factors. Material Used as Core The core is the part of the electromagnet that receives electricity. In Figure 8.15, the nail acts as the core. Iron is the best core material. This is because it easily becomes magnetic and can produce a strong magnetic field. Other materials used as electromagnetic cores are steel, cobalt and carbon. Number and Direction of Coils An increase in the number of coils increases the strength of an electromagnet. Each turn of the coil sets up its own magnetic field and contributes to the total magnetic field. The more coils that surround the core, the greater is the magnetic field of an electromagnet.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 97
The coils should loop in one direction only. If the coils loop in different directions, say some coils are clockwise and the other coils are counter-clockwise, the magnetic fields in both directions cancel each other. Electric current Another factor that contributes to the strength of an electromagnet is the amount of electric current supplied. A greater supply of electric current produces a stronger electromagnet. Activity A. Rate the strengths of the following electromagnets from 1 to 3, with 3 as the strongest: B. Put a check on each device that uses an electromagnet.
Answer the following questions: 1. How does an electromagnet work? ___________________________________________________________ __________________________________________. 2. How can the strength of an electromagnet be increased? ___________________________________________________________ __________________________________________. Go Beyond This is a compass.
Navigators use a compass to know where they are and to seek direction. Research on how a compass works. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 98
LESSON 37: SAFE AND WISE USE OF ELECTRICITY Targets State safely tips in dealing with electricity Practice safe ways of using electricity Look at the signage below. What does it show? What does it tell about electricity?
Electricity is very useful. However, improper use of electricity can be very dangerous. Protecting a Circuit Fuses and circuit breakers are devices that protect an electrical circuit. When there is too much flow of electricity, these devices automatically break the flow. A fuse contains a thin metal strip that conducts electricity. When an excessive amount of electricity flows through the fuse, it melts, breaking the circuit.
Figure 8.17.Fuses A circuit breaker also prevents the circuit from overloading. It functions like a switch that automatically opens and closes the circuit. A circuit breaker uses a more advanced technology than the fuse. Most homes today use circuit breakers rather than fuses.
Figure 8.18. A circuit breaker YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 99
Do you know where the fuse box or circuit breaker is located in your home? What is a Short Circuit? A short circuit occurs when electricity takes a shorter path in a circuit through electrical wires that touch each other. As a result, current flows from one wire to another without passing through the electrical device. Short circuits are common causes of electrical accidents like fire. Some Safety Tips in Dealing with Electricity 1. Do not plug in appliances with wet hands. Water is a conductor of electricity. You may get electrocuted. 2. Avoid using worn-out electric wires. 3. Avoid octopus connections. 4. Turn off lights and appliances when not in use. It is better to unplug them, especially during blackouts and storms. 5. Do not put your fingers or other objects into electrical sockets. 6. Report to authorities illegal connections in your place. Overloading of appliances causes explosion of transformers. 7. Hold the plug instead of the cord when disconnecting an appliance from an electrical outlet. Can you cite more ways of handling electricity safely? Wise Use of Electricity Most of our daily activities depend on electricity. However, electricity is produced by sources that we cannot renew in a short span of time. If electricity is not used properly, our electrical supply will run out. People should use electricity wisely to avoid paying high bills for our excessive electrical energy consumption. These are some saving tips that will help you use electricity wisely. 1. Turn off electrical devices that are not in use.Make sure they are disconnected from the outlets.Turned off appliances that are connected to the outlet still consume electrical energy. 2. Use natural light if possible. For areas where you frequently stay, use lamps that give direct lighting. 3. Schedule your ‗‘ironing day.‘‘. Carefully plan the clothes that you need to iron for the entire weeks. Frequently heating and reheating of the flat iron requires a lot of electrical energy. 4. Iron handkerchiefs and other small clothes using the heat of the newly turned off flat iron.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 100
5. Use compact fluorescent (CFL) instead of in candescent lamps. CFL produces more illumination and uses less electrical energy compared to an incandescent lamp with the same voltage. 6. Use an air conditioning unit with high energy efficiency rating (HEER) the higher the HEER, the more efficient is the unit and therefore the lesser the operating expenses. 7. Clean electric fans and other devices often. Dust and rust decrease the efficiency of electrical appliances. 8. Use the heat of the sun for drying clothes instead of using the electric dryer. 9. In using the microwave oven of electric stove, make sure the ingredients and materials are already prepared. This prevents frequent switching of the appliance on and off. 10.Do not spend too much time in front of the computer playing games , or browsing websites. Activity A. For each situation, list three ways of using electricity wisely. When studying 1.____________________ 2.____________________ 3. ____________________
When watching television 1.____________________ 2.____________________ 3. ____________________
When cooking 1. ___________________ 2. ___________________ 3. ___________________ B. Answer the following questions: 1. Why should one observe safety in dealing with electricity? ______________________________________________________________ ____________________________________ 2. Why is it important to use electricity wisely? _____________________________________________________________ _____________________________________ Go Beyond Electricity can be produced using sunlight. This is done through the use of solar panels. Solar panels absorb energy from the sun and transform it into electricity. Solar power is used in some places in the Philippines. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 101
The use of solar panels does not contribute to air pollution.
CHAPTER 9: SIMPLE MACHINES Lesson 38: Inclined Planes Targets: Recognize the importance of simple machines Identify the uses of inclined planes Name the forms of inclined planes, cite examples and specify their uses. Machines enable us to accomplish tasks with less effort. They help us in different ways. 1. Machines can make an object move in a different direction by changing the direction of the force applied on the object. In a Simple Pulley, when you pull the rope downward, the load moves up. 2. Machines can move an object faster and farther by multiplying its speed. To transfer bricks faster, load and push them in a wheelbarrow instead of carrying them with bare hands. 3. Machines can lift heavy objects by multiplying the force on them. 4. Machines can lift someone heavier than you on a seesaw. Inclined Plane Look at the illustration below. What do you think helps the man move the bricks? What does this show?
An inclined plane is a sloping, flat surface with one of its end higher than the other. An inclined plane is used to move objects to higher places. When moving an object up an inclined plane, the amount of force required is less than the needed force to carry the object upward. An inclined plane multiplies the amount of force one exerts on the object. It does this when the direction of the force applied is not directly opposite that of the object‘s weight.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 102
The ramps that people in wheelchairs use are inclined planes. Other examples of inclined planes are shown in Figure 9.3.
Wedges and screws are also inclined planes Wedge A wedge is like a double inclined plane that is thick at one end and thin at the other. The sloping surface tapers to a sharp edge. A wedge is usually used to cut objects. An axe is an example of a wedge .The downward force applied on it produces a horizontal force that slits an object. The narrower the wedge or the thinner its point, the greater is its driving force for splitting objects.
Figure 9.4. A wedge is used in cutting wood. Other examples of wedges are knives, scissors, chisels saws, and blades. Wedges do not always have flat surfaces. Pins and nails have round bodies.
Figure 9.5 Examples of wedges
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 103
Screw A screw can be described as a spiral-shaped plane or an inclined plane wrapped around a cylinder. The cylindrical post is called body and the ridges are collectively called thread. Screws are used to hold, move or lift objects. Most screws that are used to hold objects together have a slotted head on which the screwdriver tip is placed. The circular motion of the screwdriver tightens or loosens the screw. Screws are found in bottle caps, bases of light bulbs, drillers, and screw jacks.
Figure 9.6 Examples of screws Activity A. Classify each of the following inclined planes as wedge or screw:
1._________________
3._________________
2._______________
4._______________
5. ________________
6._____________
7.________________
8._______________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 104
9._________________
10. _______________
B. Answer the following questions: 1. How do machines make our lives more convenient? _____________________________________________________________ _________________________________________ 2. What are inclined planes? _____________________________________________________________ _________________________________________ 3. Why wedges and screws are considered inclined planes?
Go beyond In different establishments such as hotels and malls, you can see escalators moving walkways, which can be considered as moving inclined planes. People simply stand on an escalator or walkway, and the mechanism transports them up or down or to their desired destination. The first moving walkway was seen in Chicago, Illinois in 1893. Chairs were provided for passengers who wanted to sit.
a moving walkway
escalators
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 105
LESSON 39: LEVERS Targets Identify the characteristics of levers Classify the levers into three classes Name the types of pulleys Another type of simple machine is the lever. Lever comes from the French word lever, which means ‗‘to raise‘‘. A lever is a rigid object that turns about a fixed point.
Figure 9.7 Parts of a lever The effort is the force exerted by the lever to lift the object. It is the force that you apply on the lever. The distance from the point where you apply the effort to the fulcrum is called effort arm. The fulcrum is a fixed point where the lever moves freely. The resistance acts against the effort. It is the weight of the object that is moved or lifted. The resistance arm is the distance from the load to the fulcrum.
(a) (b) Figure 9.8 a. The fulcrum is nearer to the effort, than the resistance; b. the fulcrum is midway between the effort and the resistance. The closer the fulcrum is to the effort, the greater is the force needed to lift the load. When the fulcrum is closer to the resistance than to the effort, less force is required to lift the object. There are three classes of levers: first-class, second class, and third-class levers. First-Class Lever A first-class lever has its fulcrum located anywhere between the resistance and the effort.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 106
Figure 9.9.First-class lever In the first-class lever, the effort acts opposite the direction of the object‘s motion.
Figure 9.10. Example of first-class levers Second –class levers In a second-class lever, the resistance is located between the fulcrum and the effort. The effort acts in the same direction as the objects‘ motion.
Figure 9.11. Second-class lever Figure 9.12 Examples of second-class levers Third- Class Lever The effort is located between the resistance and the fulcrum in a third-class lever.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 107
Figure 9.13. Third-class lever
Figure 9.14. Examples of a third-class levers Levers are also modified into other forms such as wheels and axles and pulleys. Wheel and Axle A Wheel and axle is a simple machine that consists of two wheels of different sizes attached to each other. The smaller wheel is the axle, and the larger one is the wheel.
Figure9. 15 Wheel and axle Because the wheel and axle are connected to each other, when one turns, the other one does the same. It is either the wheel turning the axle or the axle turning the wheel. The wheel and axle is considered a first-class lever. The wheel exerts the effort, and the axle represents the resistance. The center of the axle serves as the fulcrum. One common example of wheel and axle machine is the steering wheel of a car. Other examples are pencil sharpeners, doorknobs, egg beaters and bicycles. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 108
Figure 9.16 Examples of wheels and axles Pulley A Pulley is made up of a wheel with a groove over which a rope passes. The wheel turns around an axle. The pulley is also considered a modified lever. When a person pulls the rope in a pulley, force is exerted. The load at the opposite end of the rope resists the exerted effort. The point where the rope and pulley meet is similar to a fulcrum. There are three kinds of pulleys namely, fixed, movable, and block-and tackle pulleys. Fixed Pulley A fixed pulley is attached to one place. The rope passing through the groove is tied to the load. The other end of the rope is where a pull is exerted. A fixed pulley changes the direction of the force exerted on the rope. As you pull the rope downward, the load at the other end moves upward. Fixed pulleys are used in flagpoles.
Figure. 9.17 A fixed pulley Movable Pulley As its name suggests, a movable pulley is not attached to a fixed point. It moves along with a rope. In a sigle movable pulley, the force applied acts in the same direction as the motion of the load. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 109
Figure 9.18. A single movable pulley Block-and-Tackle Pulley A block-and-tackle pulley is a combination of fixed and movable pulleys. The fixed pulleys change the direction of the force, while the movable pulleys multiply the amount of force. The more movable pulleys are used, the lesser is the force required for lifting.
Figure 9.19. A block-and-tackle pulley Activity A. Classify each of the following levers as first,second or third-class.
1.
_________________
2.
__________________
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 110
3.
4.
5.
__________________
__________________
__________________
B. Locate and label the fulcrum, resistance arm and effort arm in each picture.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 111
Go Beyond There are levers in a human body. One example is the forearm, which works like a third-class lever. The biceps are attached near the elbow. The elbow serves as the fulcrum. Whenever you pick up an object, the biceps provide the force to move the forearm bone. Load Effort
Fulcrum
LESSON 40: SAFETY IN HANDLING SIMPLE MACHINES Targets -Identify ways of properly handling simple machines -Practice safety measures in using simple machines If machines are not properly used, accidents can happen. To avoid accidents, exercise care in using and handling machines. Here are some safety measures in using machines. 1. Avoid playing with tools that have sharp and pointed tips. 2. Carefully read the instructions for proper handling, safekeeping and use of machines. 3. In carrying sharp tools, always keep the sharp tips and edges pointing downward. 4. Inspect the tools before using them. To avoid accidents, be sure that the machines are in good condition. 5. Wear protective gear when using certain machines. 6. Seek assistance from knowledgeable persons in operating and using unfamiliar tools and machines. 7. Keep tools out of the reach of children. Have the tools placed in a safety box or kit. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 112
8. For metal tools, apply lubricants, such as oil or grease, before keeping them in their proper places to prevent them from rusting. 9. Use the appropriate tool for a specific task. For example, do not use a kitchen knife in sharpening a pencil. Activity 1 Answer the following questions 1. Why should machines be used properly? ____________________________________________________________ 2. What should be done if a tool is found broken? ____________________________________________________________ 3. How can tool be kept in good condition? Give one tool and explain how you can keep it in good condition. ____________________________________________________________
Go Beyond
Astronauts also have special machines to help them install or replace components while on orbit. The tools are made simple to maximize the use of the astronauts‘ time in space. One such tool is the mini-power tool. It is a drilling tool that spins 210 revolutions per minute. It is useful to space walkers, especially in changing screws and bolts.
LESSON 40: SAFETY IN HANDLING SIMPLE MACHINES If machines are not properly used, accidents can happen. To avoid accidents, exercise care in using and handling machines. Here are some safety measures in using machines. 1. Keep simple machines in their proper places after using them. 2. Avoid playing with tools that have sharp and pointed tips. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 113
3. Carefully read the instructions for proper handling, safekeeping and use machines. 4. In carrying sharp tools, always keep the sharp tip and edges pointing downward. 5. Inspect the tools before using them .To avoid accidents, be sure the machines are in good condition. 6. Wear protective gear when using certain machines. 7. Seek assistance from knowledgeable persons in operating and using unfamiliar tools and machines. 8. Keep tools out of reach of children. Have the tools placed in a safety box or kit. 9. For metal tools, apply lubricants, such as oil or grease, before keeping them in their proper places to prevent them from rusting. 10. Use the appropriate tool for a specific task. For example, do not use a kitchen knife in sharpening a pencil.
UNIT IV EARTH AND BEYOND CHAPTER 10: ROCKS LESSON 41: CHARACTERISTICS OF ROCKS Targets:  To describe the physical characteristics of rocks  To use a scale in determining the hardness of rock samples Rocks are made up of mixtures of minerals, organic matter, and other particles. Minerals are naturally occurring inorganic chemicals on Earth. Some rocks are made up of one type of mineral. Others are composed of combinations of minerals. Scientist can tell the origin of rocks based on what they are made up of. Moreover, the characteristics of rocks reveal their mineral composition. Some characteristics of Rocks Color Rocks vary in color. Some may be red, gray greenish or even bluish. A red color usually shows the presence of iron. Greenish o r bluish rocks indicate the presence of copper. But different rocks may possess the same color. Thus, color alone is not a reliable basis in identifying the mineral composition of rocks.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 114
Streak color is the color of the powder produced by rubbing a rock with a harder material. The color of the powder sometimes differs from the color of the rock.
Luster Luster is the ability of a mineral to reflect light. The quality of reflected light depends on the metallic or non-metallic property of a rock. Metallic rock such as those that contain gold, are shiny. Nonmetalic rocks, such as those with talc, are dull and not shiny.
Texture A rock may be smooth, rough or earthy when touched .The texture of rock depends on the size of mineral crystals or grains in it.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 115
Cleavage and Fracture Cleavage and fracture describe how rocks break. The manner by which rock breaks depends on the structure of their minerals. The tendency of a mineral to split in one direction, forming thin sheets or flat surfaces, is called cleavage. Many minerals break along planes or flat surfaces, like mica and calcite. A broken rock may form flat surfaces in one or more directions , but some breakage may not be flat. Irregular, rough or jugged edges in broken rocks form fracture. Most metallic rocks form hackly fracture.
Hardness A mineral‘s resistance to scratching is called hardness. Hardness is determined by scratching the mineral with another mineral of known hardness. In the field, you can identify the hardness of some minerals by using the things that you have with you. This is called field scale of hardness.
Scale 1
Table 10.1 Field Test descriptions Mineral Test Easily turns to powder using finger nail
2
Scratchable with a fingernail
3
Scratchable with a copper coin
4
Easily scratchable with a knife
5
Scratchable with a knife
6
Scratchable with a steel knife
7
Scratches steel file
8
Easily scratches quartz
9
Easily scratches topaz
10
Cannot minerals
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
be
scratched,
hardest
of
all
Page 116
The German geologist Friedrich Mohs developed a scale for measuring rock hardness. In the Mohs Scale of Hardness, the unknown hardness of a mineral is compared to the known hardness of other minerals.
Source:https://www.bestcrystals.com/hardness.html
Activity 1 A. Tell whether the statement is true or false. Write your answers on the blank. ______1. Rocks dominate the earth‘s crust. ______2. Diamond is the hardest mineral. ______3. The ability of a rock to resist scratching determine ots hardness. ______4. Nonmetallic rocks give off a polished shine. ______5. Cleavage is the tendency of a mineral to break into regular parts. B. Identify the characteristics of rocks that each statement implies. 1. An iron nail can scratch a piece of chalk. _______________________________________________________ 2. Obsidian breaks into pieces when it falls on a solid surface. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 117
_______________________________________________________ 3. Gold is widely used in jewelry making because of its shiny appearance. _______________________________________________________ 4. Jade may qualify as an attractive pendant because of its green color. ______________________________________________________ 5. Pumice is commonly used as a body scrub because it is coarse. ______________________________________________________
LESSON 42: FORMATION OF ROCKS Targets To Identify Different Kind Of Rocks To explain how different rocks are formed To explain the rock cycle Geologists are people who study the earth and its composition. They group rocks based on where they are formed. Rocks can be categorized into igneous, sedimentary and metamorphic rocks. Igneous rocks Igneous rocks are formed from magma or lava. Beneath the earth‘s crust is a tremendous amount of heat that continuously melts solid rocks. The mixture of molten rocks, gases and mineral crystals is referred to as magma. Magma that has reached the surface of the earth is called lava. Igneous rocks can be classified into two. Extrusive igneous rocks are those rocks that are cooled and formed on the earth‘s surface. These rocks are fine grained with small mineral crystals. Examples of extrusive igneous rocks are basalt and pumice. Igneous rocks that are formed from magma that has solidified within the earth‘s crust are called intrusive igneous rocks. These are coarse grained with big crystals. Gabbro and granite are some examples of intrusive igneous rocks.
Pumice
basalt
granite
gabbro
(a) (b) Figure 10.6. (a) example of extrusive igneous rocks;)b) intrusive igneous rocks
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 118
Igneous rocks are useful to people. Basalt is used in construction as a building block. Gabbro is widely used as a paving material. Pumice is used asan abrasive material in hand soaps and emery boards. Granite is commonly used in making monuments. Sedimentary rocks Sedimentary rocks, as the term suggests are formed from sediments. Sediments are loose particles from plant and animal remains .These sediments may contain rock fragments. They are carried by wind, water and other agents. They are deposited and compacted to form sedimentary rocks. Some sedimentary rocks are formed from fragments or loose particles of other rocks. They are called clastic sedimentary rocks. Examples of these are conglomerate, breccias, sandstone and shale.
Figure 10.7 Some clastic sedimentary rocks Some sedimentary rocks are formed from chemical sediments. These chemical sediments are dissolved in lakes and seas. When water evaporates, the minerals accumulate and form sedimentary rocks. Rocks that have formed through this process are called chemical sedimentary rocks.
Rock salt sylvite gypsum Figure 10.8 some chemical sedimentary rocks
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 119
Sedimentary rocks that have formed from the remains of plants and animals are known as organic sedimentary rocks. These rocks reveal information about Earth‘s distant past because of the plant and animal remains they contain. Scientists have found preserved fossils in some organic rocks.
Coal
coquina limestone Figure 10.9. Some organic sedimentary rocks
Metamorphic rocks Some rocks are buried in great depths. Temperature and pressure increase as depth increases. When temperature and pressure act on a rock, they change its texture and composition and a metamorphic rock forms. Metamorphism is the process by which a rock changes to become a metamorphic rock without melting. The word metamorphism is derived from the Greek words meta, meaning ‗‘change‘‘ and morphe, meaning ‗‘ form‘‘. Gneiss is a metamorphic rock that forms from granite, which is an igneous rock. When a high temperature and pressure act upon shale ( a sedimentary rock , it becomes slate ( a metamorphic rock). Some examples of metamorphic rocks are quartzite, marble, slate and gneiss. Rock Cycle Once a rock is formed, does it stay the same for the next thousands of years? Rocks undergo continuous changes as a result of the different processes in nature. The continuous changing and remaking of rocks is called the rock cycle.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 120
The rock cycle begins under the earth‘s crust where magma is found. Volcanic eruption releases magma from under the crust. Magma that cools within the earth‘s crust becomes intrusive igneous rocks. The released magma that cools on the surface forms extrusive igneous rocks. In time extrusive igneous rocks are eroded and washed away by wind and water. Two process affect the movement of eroded rocks-weathering and erosion. Weathering is a physical process that breaks down rocks into pieces. Erosion takes place when the rock fragments or sediments are moved and transported by wind, water, animals, and other agents. Both weathering and erosion break the rocks into sediments. These sediments are pressed together, forming sedimentary rocks. Some sedimentary rocks end up under the earth‘s crust. Due to heat and pressure, sedimentary rocks are transformed into metamorphic rocks. Metamorphic rocks that are underground are then melted into magma and the rock cycle starts again. Activity A. Identify the rocks that are formed by each process. Write the word igneous, sedimentary or metamorphic. ____________1. A volcano erupts and spews lava around it.The lava cools after some time. ____________2. Plants are buried underground and form coal. ____________3. Due to global warming,some rivers have dried out. ____________4. High pressure and temperature change the compositionof some rocks. ____________5. Shells of dead marine animals settle and deposit on the ocean floor.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 121
B. Classify the rocks. Write I on the blank for igneous, S for Sedimentary and M for metamorphic. _________1. Basalt ________6. Pumice _________2. Sandstone ________7. Marble _________3. Gabbro ________8. Slate _________4. Granite ________9. Gneiss _________5. Quartzite ________10. shale Go beyond One of the most amazing rock formations in the world is the gnat‘s Causeway in Northern Ireland. It is an area where at least 40,000 interlocking basalt columns are found. Basalt is an extrusive igneous rock.The Giant‘s Causeway is a result of an ancient volcanic eruption.
CHAPTER 11 LESSON 43: HEAT, AIR AND WEATHER Weather is the state of the atmosphere in a certain place within a short period of time. When we talk about weather, we are referring to short-term changes in the atmosphere. Climate, on the other hand, describes the long-term condition of the atmosphere. Unequal Heating and Cooling of Earth’s Surface Land and water absorb and release heat at different rates. Land absorbs heat faster than water. This is because heat is absorbed only at the surface of land. In addition, land is solid and its molecules are highly compact, thus heat ravels Faster in it. Water, on the other hand, absorbs heat into its entire body so it takes a longer time to heat it..Moreover it takes some time for water to absorb heat because its molecules are not that compact. Land also releases heat faster than water. Since only the surface of the land gets hot during the day, it releases the absorbed heat faster when night comes.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 122
Sea Breeze and Land Breeze
The unequal heating and cooling of the earth‘s surface causes air to move.How does this happen? During the day, the land is warmer than the sea.The air over the land is also warmer than the air over the sea.Warm air,which has low air pressure,rises.Low air pressure means that there is less weight of air pushing on the area below it. The cool air over the sea moves toward the land.Cool air has greater pressure and is thus heavier, so it tends to replace the rising warm air.This is why we feel a cool wind blowing from the sea to the land during the day.This is called sea breeze.At night, the opposite happenss.Land releases heat faster than water.it therefore cools faster than water. The cool air over the land moves toward the sea.This is called land breeze. The difference in air pressure creates the movement of air.Air always moves from an area of greater pressure to an area of lower pressure. Air Masses An air mass is a large body of air that has relatively uniform temperature and amount of water vapor (humidity ).Air masses are formed over land and seas.Those that are formed over land have less exposure to moisture,so they are drier than those that are formed over seas. Fronts Air masses with different characterisitics sometimes collide, forming a front. A front is a narrow region separating two air masses. The interaction of colliding air masses causes dramatic changes in weather. When cold dense air advances and displaces warm air, a cold front is formed. The cold air forces the warm air up and moves under it. Clouds, showers, and sometimes thunderstorms are associated with cold fronts. In a warm front, advancing warm air displaces and rides over cold air. A warm front is characterized by extensive cloudiness and precipitation. Sometimes, two air masses meet without advancing or displacing each other. A a result, the boundary between them stalls, or stops moving. This type of front is called
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 123
stationary front. This kind of front brings extensive cloudiness and heavy precipitation. When a cold air mass moves so rapidly, it overtakes a warm air mass. The overtaking cold air lifts the warm air upward and collides with another advancing cold air mass. As a result, the warm air mass is squeezed upward between two cold air masses. This is called an occulent front. An occulent front results in many days of light precipitation. Wind systems
Air masses with different characteristics sometimes collide, forming a front. A front is a narrow region separating two air masses. The interaction of colliding air masses causes dramatic changes in weather.  When cold air advances and displaces warm air, a cold front is formed. The cold air forces the warm air up and moves under it. Clouds, showers and sometimes thunderstorms are associated with cold fronts.  
In a Warm front, advancing warm air displaces and rides over cold air.A warm front is characterized by extensive cloudiness and precipitation. Sometimes two air masses meet without advancing or displacing each other. As a result the boundary between them stalls, or stops moving.This type of
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 124
front is called stationary front. This kind of front brings extensive cloudiness and heavy precipitation. 
When a cold air moves so rapidly, it overtakes a warm air mass.The overtaking cold air lifts the warm air upward and collides with another advancing cold air mass. As a result, the warm air mass is squeezed upward between two cold air masses. This is called an occluded front. An occluded front results in many days of light precipitation.
Activity A. Write true on the blank if the statement is correct and false if it is incorrect. __________1.Land releases heat faster than water. __________2. Wind flows from an area of greater pressure to an area of lower pressure. __________3.Sea breeze happens at nighttime. __________4.When advancing cold air moves under warm air,a cold frot is formed. __________5.Rising warm air has less pressure than cold air.
LESSON 44: WIND SYSTEMS Earth rotates from west to east. This rotation causes the Coriolis effect. The Coriolis effect causes moving particles, such as air, to be deflected to the right in the northern hemiphere and to the left in the southern hemisphere. This deflection creates distinct global wind systems that transport warmer air to colder areas and colder air to warmer areas. Thus, the warmer air from the equator does not really go straight to the poles. The wind distribution across the globe is influenced by high and low pressure areas as well as the Coriolis effect. Recall that wind blows from an area of greater pressure to an area of lower pressure. Because of Coriolis effect, there are three basic wind systems in each hemisphere.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 125
The trade wind occur within the 30 North and South latitudes at these locations, air sinks, warms, and moves toward the equato in westerly directions. When this air reaches the equator, it warms and rises. As it rises, it moves back toward the 30 latitude where it sinks again, warms, and moves toward the equator. The second wind system consists of the prevailing westerlies. These flow between the 30 and 60 latitudes. They move in an easterly direction toward the poles. This wind system is responsible for much of the weather in the US and Canada. The polar easterlies are winds that occur between the 60 latitudes and the poles. In both hemispheres, the polar easterlies are characterized by cold air. In the northern hemisphere, wind blows from northeast to southwest. The wind direction is reversed in the southern hemisphere. Wind Systems That Affect the Philippines Monsoons Because the Philippines is located between the 4°21‘ and 21°25‘ north latitudes, its weather is affected by the trade winds. Trade winds that originate from the northeast towards the southwest are known as northeast trade winds. Also known as northeast monsoon or hanging amihan, this trade wind brings dry and warm weather from November to April. It also draws cold dry air from icy Siberia, Japan, and China. Southeast trade winds originate from the southeast toward the northwest. Locally known as the southwest monsoon or hanging habagat, this wind system becomes the prevailing wind system in the country, bringing rains from May to October. When places in Asia and those nearby get warmer than the surrounding oceans, a low-pressure are develops. The wind rushing toward the low-pressure area carry heat and vapor. Intertropical Convergence Zone Near the equator, the trade winds move together from two opposite directions. The northeast trade winds and southeast trade winds converge. The convergence of these two wind systems creates an area of low pressure. This area is characterized by rising warm air with little or no winds. The large area where the union of northeast trade winds and southeast winds occurs is called intertropical convergence zone (ITCZ). This area is characterized by a band of cloudiness and occasional rain showers.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 126
LESSON 45 TYPHOONS The word tropics refers to areas in the globe that lie between 23.5o north and 23.5o south of the equator. Areas in the tropics eceive direct rays from the sun, thus making the oceans warmer. Because it is a tropical country, it is prone to typhoon visits. Most typhoons came from the Pacific Ocean. A cyclone is an area characterized by low pressure because of the huge amount of rising warm air. This pressure is much lower than the pressure of the surrounding area. Due to the difference in pressure, cold air moves to the low pressure area, replacing warm air. A cyclone is accompanied by thunderstorms and circulation of winds near the earth‘s surface due to the Coriolis effect. In the northern hemisphere, the circulation of winds near the earth‘s surface due to the Coriolis effect. In the northern hemisphere, the circulation of winds is in the counterclockwise direction. Tropical cyclones are called typhoons in areas near the Northwestern Pacific Ocean and Indian Ocean. They are also known as hurricanes in areas near the Northern Atlantic Ocean, the northeastern Pacific Ocean, and the Caribbean. Australians call the tropical cyclones willy-willy. Stages in the Formation of Typhoons Typhoons require two basic conditions to form; a rich suppy of very warm ocean water and some sort of disturbance to lift warm air and keep it rising. A typhoon starts as a tropical disturbance, which is characterized by a concentration of cumulonimbus clouds. As more warm air rises and cools, more heat is released into the surroundings. As a result, cooler air is drawn into the low-pressure area and begins to turn. This stage is now called tropical depression. As the pressure becomes even lower, the depression feeds more warm air and the wind blows faster. A tropical storm develops when the wind reaches a speed of 63 to 117 kilometers per hour (kph). It travels and draws more and more water vapor from the ocean. A storm develops in typhoon when the wind exceeds 117 kph. A typhoon has an eye at its center. The eye of the typhoon is an area of calmness. Its size defines the typhoon velocity. A bigger eye usually means lower velocity. A bigger eye usually means lower velocity. The strongest winds are usually concentrated in a band surrounding the eye called eyewall. A typhoon lasts until it can no longer sustain itself. This happens when the typhoon moves over land and no longer has access to the warm ocean surface. Public Storm Signals in the Philippines The Philippine Atmospheric, Geophysical and Astronomical Services Administration forecasts the weather condition in the country. Meteorologists use different instruments to gather information about the atmosphere. PSWS #1 - Tropical cyclone winds of 30 km/h (19 mph) to 60 km/h (37 mph) are expected within the next 36 hours. (Note: If a tropical cyclone forms very close to the area, then a shorter lead time is seen on the warning bulletin.) PSWS #2 - Tropical cyclone winds of 60 km/h (37 mph) to 100 km/h (62 mph) are expected within the next 24 hours. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 127

PSWS #3 - Tropical cyclone winds of 100 km/h (62 mph) to 185 km/h (115 mph) are expected within the next 18 hours.  PSWS #4 - Tropical cyclone winds of greater than 185 km/h (115 mph) are expected within 12 hours. These storm signals are usually raised when an area (in the Philippines only) is about to be hit by a tropical cyclone. As a tropical cyclone gains strength and/or gets nearer to an area having a storm signal, the warning may be upgraded to a higher one in that particular area (e.g. a signal No. 1 warning for an area may be increased to signal #3). Conversely, as a tropical cyclone weakens and/or gets farther to an area, it may be downgraded to a lower signal or may be lifted (that is, an area will have no storm signal). Classes for Preschool are canceled when Signal No. 1 is in effect. Elementary and High School classes and below are cancelled under Signal No. 2 and classes for Colleges and Universities and below are cancelled under Signal No. 3 and Signal No. 4. Test Yourself Arrange A. Arrange the stages of typhoon development by writing the numbers 1 to 3 on the blanks. ___________1. The accumulated clouds start to spin,forming a tropical depression. ___________2. The apparent rising of warm air leads to the formation of a tropical disturbance. ___________Circular bands of clouds circulate at a speed of 633 to 117 kph. B. Complete the table below. Public Storm Signal Number
Atmospheric Condition
LESSON 46: WEATHER FORECASTING AND EFFECTS OF TYPHOON Effects of Typhoons Typhoons can cause a lot of damage. These damages are mostly due to strong winds and heavy rainfall. One threat along coastal areas is the possible occurrence of a storm surge. It happens when strong winds drive ocean water to coastal areas.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 128
These strong winds cause the ocean water to rise higher than the normal sea level. Sometimes a storm surge reaches 6 meters above the normal sea level. In September 2011.the typhoon Pedring brought a destructive storm surge on the coastal area of Manila Bay. Heavy and continuous rainfall can also bring adverse effects, such as landslides and mudflow. Rivers, canals, and drainages may overflow leading to heavy flood. A flood can destroy rice and crop fields. The risk of contracting waterborne diseases after a typhoon is also high due to flood. Due to strong winds and heavy flooding of streets, the supply of electric may also be affected. As the typhoon increases in strength, some electric posts may be knocked down, leading to brownout or blackout in some areas. A flood may also cause contamination of water reservoirs, water pipes and wells. Floodwater may enter worn-out water pipes that lead to household faucets. Weather Forecasting Based on the observations of the atmosphere, meteorologists make a weather forecast. To make a weather forecast, meteorologists analyze and interpret the data gathered from whether instruments. Surface data gathering includes the use of weather instruments such as thermometer, barometer, anemometer, hygrometer. Recall how these instruments. The weather that we experience is largely the result of the changes that take place in the layer of the atmosphere called troposphere. The radiosonde is a weather instrument that is used to gather upper-level data from this layer. It is carried to the atmosphere by a weather baloon. A radiosonde has that measure temperature, air pressure and humidity. The gathered data are sent by a radio signal to a ground station that tracks the weather balloon.
Fig. 11.18.Some weather instruments
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 129
Weather forecasting also makes use of weather satellites. Cameras mounted aboard a satellite take pictures of Earth from time of time. These images are beamed back to ground stations.
CHAPTER 12 THE SOLAR SYSTEM LESSON 47: THE SUN The Sun Is a Star A star is a big ball of hot gases in space. It gives off its own light. Our sun is a star. Its distance from earth is about 150,000,000 kilometres(km) Light from the sun reaches our planet in 8 minutes.
Parts of the Sun The sun is a huge ball of hot gases that are held together by gravity.These gases are mostly hydrogen and helium. The sun‘s atmsphere is divided into layers. The sun is composed of gas. It has no solid surface. However, it still has a defined structure. The three major structural areas of the sun are shown in the upper half of Figure 1. They include: Core -- The center of the sun, comprising 25 percent of its radius. Radiative zone --The section immediately surrounding the core, comprising 45 percent of its radius. Convective zone -- The outermost ring of the sun, comprising the 30 percent of its radius. Above the surface of the sun is its atmosphere, which consists of three parts, shown in the lower half of Figure 1: Photosphere -- The innermost part of the sun's atmosphere and the only part we can see.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 130
Chromosphere -- The area between the photosphere and the corona; hotter than the photosphere. Corona -- The extremely hot outermost layer, extending outward several million miles from the chromosphere.
All of the major features of the sun can be explained by the nuclear reactions that produce its energy, by the magnetic fields resulting from the movements of the gas and by its immense gravity. It begins at the core. Solar Activities There are activities that change overtime.These include sunspots,solar flares,solar prominences and solar wind. Sunspots refer to regions of the sun‘s photosphere that appear dark.Sunspots are not really dark.They just appear darker than the surrounding areas because they are cooler.They are located in areas with very strong magnetic fields. These magnetic fields prevent hot gasesfrom the sun‘s interior to rise at the surface. Typically sunspots last for two months.Some last for only few days. Solar flares- are violent eruptions from the sun‘s surface.They are associated with sunspots,as they too are caused by the sun‘s magnetic field.Often the released particles escape the sun‘s gravity and travel through space.Large solar flares obstruct radio communications. Solar prominences are arches of gases that are ejected from the sun‘s chromosphere.Unlike flares,prominences rain back o the sun‘s surface. The sun‘s corona ejectts astream of charged particles called solar wind.The speed of solar wind varies from 400 to 800 km per second. Activity Match each word in column A with its description in column B. Write the letter of your answer on the blank. A B __________1. Photosphere a. Visible only during solar eclipse __________2. Corona b. a violent eruption from the sun‘s surface __________3. Sunspot c. the sun‘s visible surface __________4. Solar flare d. An area of strong magnetic field __________5. Solar prominence e. An arch of ejectedd gases that goes back to the sun‘s surface.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 131
LESSON 48: THE PLANETS Planets are spherical celestial bodies that revolve around a star,are massive and have an atmosphere.They have no light on their own.Each planet revolves around th sun following an imaginary path called orbit.Planets in the solar system can be grouped into two.known as inner planets because of their nearness to the sun.These planets are Mercury,Venus,Earth and Mars. Terrestrial planets Terrestrial planets are those that are like earth in terms of density and composition.They hav solid and rocky surfaces.These planets are also Mercury
The closest planet to the sun, Mercury is only a bit larger than Earth's moon. Its day side is scorched by the sun and can reach 840 degrees F (450 C), but on the night side, temperatures drop to hundreds of degrees below freezing. Mercury has virtually no atmosphere to absorb meteor impacts, so its surface is pockmarked with craters, just like the moon. Discovery: Known to the ancients and visible to the naked eye Named for: Messenger of the Roman gods Diameter: 3,031 miles (4,878 km) Orbit: 88 Earth days Day: 58.6 Earth days
Venus
The second (2nd) planet from the sun, Venus is terribly hot. The atmosphere is toxic. The pressure at the surface would crush and kill you. Scientists describe Venus‘ situation as a runaway greenhouse effect. Its size and structure are similar to Earth, Venus' thick, toxic atmosphere traps heat in a runaway "greenhouse effect." Oddly, Venus spins slowly in the opposite direction of most planets.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 132
The Greeks believed Venus was two different objects — one in the morning sky and another in the evening. Because it is often brighter than any other object in the sky — except for the sun and moon — Venus has generated many UFO reports. Discovery: Known to the ancients and visible to the naked eye Named for: Roman goddess of love and beauty Diameter: 7,521 miles (12,104 km) Orbit: 225 Earth days Day: 241 Earth days Earth
An image of the Earth taken by the Russian weather satellite Elektro-L No.1. The third (3rd) planet from the sun, Earth is a waterworld, with two-thirds of the planet covered by ocean. It‘s the only world known to harbor life. Earth‘s atmosphere is rich in life-sustaining nitrogen and oxygen. Earth's surface rotates about its axis at 1,532 feet per second — slightly more than 1,000 mph — at the equator. The planet zips around the sun at more than 18 miles per second. Diameter: 7,926 miles (12,760 km) Orbit: 365.24 days Day: 23 hours, 56 minutes Related: More Earth Information 50 Amazing Facts about Earth Earth Pictures
Mars
Mars researchers are focusing both Earth-based and planet orbiting sensors to better understand sources of methane on the red planet. Image Credit: Space Telescope Science Institute The fourth (4th) planet from the sun, is a cold, dusty place. The dust, an iron oxide, gives the planet its reddish cast. Mars shares similarities with Earth: It is rocky, has mountains and valleys, and storm systems ranging from localized YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 133
tornado-like dust devils to planet-engulfing dust storms. It snows on Mars. And Mars harbors water ice. Scientists think it was once wet and warm, though today it‘s cold and desert-like. Mars' atmosphere is too thin for liquid water to exist on the surface for any length of time. Scientists think ancient Mars would have had the conditions to support life, and there is hope that signs of past life — possibly even present biology — may exist on the Red Planet. Discovery: Known to the ancients and visible to the naked eye Named for: Roman god of war Diameter: 4,217 miles (6,787 km) Orbit: 687 Earth days Day: Just more than one Earth day (24 hours, 37 minutes) Related: More Mars Facts Mars Pictures Jovian Planets
The Jovian planets are called such because they carry the same characteristics as those of the planet Jupiter. Jovian planets are larger than the terrestrial planets, more gaseous and lack solid surfaces. They are also known as outer planets because of their remoteness from the Sun. The outer planets are Jupiter, Saturn, Uranus and Neptune. Jupiter The fifth (5th) planet from the sun, Jupiter is huge and is the most massive planet in our solar system. It‘s a mostly gaseous world, mostly hydrogen and helium. Its swirling clouds are colorful due to different types of trace gases. A big feature is the Great Red Spot, a giant storm which has raged for hundreds of years. Jupiter has a strong magnetic field, and with dozens of moons, it looks a bit like a miniature solar system. Discovery: Known to the ancients and visible to the naked eye Named for: Ruler of the Roman gods Diameter: 88,730 miles (428,400 km) Orbit: 11.9 Earth years Day: 9.8 Earth hours
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 134
The shadow of Saturn's moon Mimas dips onto the planet's rings and straddles the Cassini Division in this natural color image taken as Saturn approaches its August 2009 equinox. Credit: NASA/JPL/Space Science Institute Saturn The sixth (6th) planet from the sun is known most for its rings. When Galileo Galilei first studied Saturn in the early 1600s, he thought it was an object with three parts. Not knowing he was seeing a planet with rings, the stumped astronomer entered a small drawing — a symbol with one large circle and two smaller ones — in his notebook, as a noun in a sentence describing his discovery. More than 40 years later, Christian Huygensproposed that they were rings. The rings are made of ice and rock. Scientists are not yet sure how they formed. The gaseous planet is mostly hydrogen and helium. It has numerous moons. Discovery: Known to the ancients and visible to the naked eye Named for: Roman god of agriculture Diameter: 74,900 miles (120,500 km) Orbit: 29.5 Earth years Day: About 10.5 Earth hours
Near-infrared views of Uranus reveal its otherwise faint ring system, highlighting the extent to which the planet is tilted. Credit: Lawrence Sromovsky, (Univ. Wisconsin-Madison), Keck Observatory Uranus The seventh (7th) planet from the sun, Uranus is an oddball. It‘s the only giant planet whose equator is nearly at right angles to its orbit — it basically orbits on its side. Astronomers think the planet collided with some other planet-sized object long ago, causing the tilt. The tilt causes extreme seasons that last 20+ years, and the sun beats down on one pole or the other for 84 Earth-years. Uranus is about the same size as Neptune. Methane in the atmosphere gives Uranus its blue-green tint. It has numerous moons and faint rings. Discovery: 1781 by William Herschel (was thought previously to be a star) Named for: Personification of heaven in ancient myth Diameter: 31,763 miles (51,120 km) Orbit: 84 Earth years Day: 18 Earth hours
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 135
Neptune‘s winds travel at more than 1,500 mph, and are the fastest planetary winds in the solar system. Credit: NASA/JPL Neptune The eighth (8th) planet from the sun, Neptune is known for strong winds — sometimes faster than the speed of sound. Neptune is far out and cold. The planet is more than 30 times as far from the sun as Earth. It has a rocky core. Neptune was the first planet to be predicted to exist by using math, before it was detected. Irregularities in the orbit of Uranus led French astronomer Alexis Bouvard to suggest some other might be exerting a gravitational tug. German astronomer Johann Galle used calculations to help find Neptune in a telescope. Neptune is about 17 times as massive as Earth. Discovery: 1846 Named for: Roman god of water Diameter: 30,775 miles (49,530 km) Orbit: 165 Earth years Day: 19 Earth hours
Pluto and its moons orbit the sun near the edge of our solar system.Learn all about Pluto's weirdly eccentric orbit, four moons and more in this Space.com infographic. Credit: SPACE.com/Karl Tate Pluto (Dwarf Planet) The ninth (9th) planet from the sun … well … Pluto is unlike other planets in many respects. It is smaller than our moon. Its orbit carries inside the orbit of Neptune and the way out beyond that orbit. From 1979 until early 1999, Pluto had actually been the eighth planet from the sun. Then, on Feb. 11, 1999, it crossed Neptune's path and once again became the solar system's most distant planet — until it was demoted to dwarf planet status. Pluto will stay beyond Neptune for 228 years. Pluto‘s orbit is tilted to the main plane of the solar system — where the other planets orbit — by 17.1 degrees. It‘s a cold, rocky world with only a very ephemeral atmosphere. Discovery: 1930 by Clyde Tombaugh Named for: Roman god of the underworld, Hades Diameter: 1,430 miles (2,301 kilometers) Orbit: 248 Earth years Day: 6.4 Earth day YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 136
Test Yourself. Match each word in Column A with its description in column B. Write on the blank letter of your answer. A B ------------1.planet a. It is the hottest planet ______2. Jupiter b. It has a spectacular ring system ______3. Mercury c. It is a spherical celestial body revolving a round a star. ______4. Earth d. Its prominent feature is the Great Red spot. ______5. Mars e. It is the closest planet to the sun ______6.Saturn f. It travels around the sun on its side. ______7. Uranus g. Triton is its largest moon ______8. Neptune h. It is known as the red planet ______9. Venus It is now considered a dwarf planet ______10. Pluto i. It is the third planet from the sun.
LESSON 49 OTHER MEMBERS OF THE SOLAR SYSTEM
Asteroids are small, airless rocky worlds revolving around the sun that are too small to be called planets. They are also known as planetoids or minor planets. In total, the mass of all the asteroids is less than that of Earth's moon. But despite their size, asteroids can be dangerous. Many have hit Earth in the past, and more will crash into our planet in the future. That's one reason scientists study asteroids and are eager to learn more about their numbers, orbits and physical characteristics. If an asteroid is headed our way, we want to know that. Most asteroids lie in a vast ring between the orbits of Mars and Jupiter. This main asteroid belt holds more than 200 asteroids larger than 60 miles (100 kilometers) in diameter. Scientists estimate the asteroid belt also contains more than 750,000 asteroids larger than three-fifths of a mile (1 km) in diameter and millions of smaller ones. Not everything in the main belt is an asteroid — for instance, comets have recently been discovered there, and Ceres, once thought of only as an asteroid, is now also considered a dwarf planet.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 137
Many asteroids lie outside the main belt. For instance, a number of asteroids called Trojans lie along Jupiter's orbital path. Three groups — Atens, Amors, and Apollos — known as near-Earth asteroids orbit in the inner solar system and sometimes cross the path of Mars and Earth. Comets
Comets Comets are small icy bodies orbiting the Sun .Some comets have orbits that stretch beyond the orbit of Pluto.Others are very close to the sunWhen a comet comes close to the sun,it begins to evaporate.The resulting gases fly away from the sunn,forming the oma and tail.The coma is the extended volume of glowing gases around a solid core called nucleus. A comet may have one or more tails.The tails are pushed away by particles and pressure from the sun.This explains why the tails of comets always point away from the sun. The nearest comet to the sun is Encke’s comet.It returns every 3.3 years.it is classified as a short term comet.This kind of comet reappears near earth in less than 200 years.Halley‘s comet is known asa well-known short comet witha 76 year period.It last appeared in 1985 to 1986,and it is expected to reappear in 2061.A comet that takes longer than 200 years to reappear is called a long-term comet. Meteoroids
As asteroids and comits orbits,they occassionally break into fragments.Rock fragments as large as bouders or as fine as sand are formed.These fragments are called meteoroids. YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 138
When a meteoroids travels around earth, it burns up in the atmosphere and produces a flash of light in the sky. A meteoroid is called a meteor when it enters the atmosphere. Sometimes it is referred to as a shooting star. However, meteoroids are not stars. Most meteors completely burn just before they touch earth‘s surface. Meteoroids that does not completely disintegrate reach the ground and are then called meteorites.
Activity 1. ________________are small icy bodies orbiting the sun. 2. Scientists believe that ______________are leftovers from the formation of the solar system. 3. Between Mars and Jupiter is an area where most asteroids are found. This area is called___________________. 4. The _______________is a comets solid core. 5. A _________________ produces a streak of light as it burns up in the atmosphere.
YOUNG JI INTERNATIONAL SCHOOL/COLLEGE
Page 139