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FINAL: STRUCTURE AND FUNCTION OF THE FOLLOWING __Cell division and Chromosomes__ mitosis 107 interphase prophase meta phase anaphase telophase cytokinesis replication chromatin sister chromatids centromere meiosis chromosome homologous pair variation

__Inheritance and genetics__ genetics 130 trait purebred hybrid genes allele dominant allele recessive allele genotype phenotype homozygous heterozygous Punnett square test cross pedigree carrier incomplete dominance codominance polygenic trait multiple alleles pleiotropy

__DNA and Chromosomes__ DNA 158 nitrogenous bases double helix replication linked genes crossing over autosomes sex chromosomes sex-linked genes karyotype genome nondisjunction trisomy

__Genes and Genetic expression__ RNA 182 mRNA tRNA ribosome amino acid transcription translation codon anticodon mutation

__Human Body__ 692 axial skeleton appendicular skeleton marrow red marrow yellow marrow osteoblasts spongy bone compact bone periosteum Haversian canal ball-and-socket joint hinge joint pivot joint gliding joint immovable joint tendon ligament flexor extensor skeletal muscle cardiac muscle smooth muscle muscle fiber myofibril sarcomere integumentary system epidermis dermis subcutaneous follicle melanin nutrient 720 carbohydrates lipids essential amino acids enzyme mouth saliva esophagus peristalsis stomach hydrochloric acid pepsin small intestine villi lacteal colon feces liver gallbladder pancreas kidneys nephron glomerulus Bowman's capsule renal tube reabsorption capillary secretion filtration ureter urethera renal artery renal vein

1. The pharynx is the region in the back of the throat. 2. The epiglottis covers the trachea when something is swallowed. 3. The trachea is the “wind pipe” that air travels through to reach the lungs. 4. The long muscular tube that moves food from the pharynx is the esophagus. 5. The successive waves of smooth muscle contraction that moves food through the digestive track is called peristalsis. 6. The mixing of food by stomach contractions continues mechanical digestion. 7. Hydrochloric acid and the enzyme pepsin chemically breaks down protein in the stomach. 8. Mucus lubricates the digestive tract and coats the stomach lining to protect it from digestive fluids. 9. The digestion of carbohydrates and protein is completed in the small intestine. 10. Fats are digested in the small intestine by enzymes and bile. 11. Villi line the internal surface of the small intestine, increasing its surface area for absorption. 12. Nutrients absorbed by the small intestine pass into blood and lymph vessels in the villi. 13. The small intestine passes undigested material through a valve to the large intestine. 14. In the large intestine, water and water-soluble vitamins are absorbed from the undigested material. 15. Once the water has been removed, the solid undigested material is called feces. 16. The distance food moves through the digestive tract is about 27 feet. 17. The liver, gallbladder, and pancreas each play a key role in digestion. 18. The liver further processes carbohydrates, proteins, and fats in the blood. 19. the liver produces bile for the gallbladder and breaks down toxins. 20. The gallbladder concentrates bile and delivers it through duct to the small intestine. 21. The pancreas produces enzymes which are delivered through ducts to the small intestine. 22. The pancreas also produces insulin which controls sugar in the blood.
 * 1) 73......Digestion 2 / Two Column Notes......6/1/09


 * 1) 72......Extra Credit


 * 1) 71......Sense Video......5/29

Worth double points. Must be turned at the end of class period to earn any points. If you didn't work or didn't turn in your paper at the end of clas, you earned a zero. Only absent students can make up this assignment.
 * 1) 70......Two Column Notes

1. The mechanical and chemical breaking down of food is called digestion. 2. The teeth start mechanical digestion in the mouth. 3. Chemical digestion starts in the mouth by saliva from the salivary glands 4. The carbohydrates in whole grain should be peoples main source of energy. 5. Sugars and starches are examples of the two categories of carbohydrates. 6. Nutrients are absorbed into the blood for transport to other body cells. 7. Fats and oils are compounds called lipids. 8. Cells use lipids to form membranes and to store energy like in fat cells. 9. A glycerol and three chains of fatty acids result from the digestion of lipids. 10. Unsaturated fats in plants are better for you than saturated fats in meat and processed food.(rewrite using worst) 11. Saturated fats have few double bonds between carbon atoms while unsaturated fats have many. 12. Saturated fats are solid at room temperature while unsaturated fats are liquid. 13. Structures in the body are constructed of thousands of different kinds of proteins. 14. 20 kinds of amino acids are the building blocks that make up all proteins. 15. Eight amino acids are called essential and people only get them from food. 16. Proteins are broken down into their amino acids by digestion. 17. Proteins that assist in chemical reactions are called enzymes. 18. Vitamins work in conjunction with enzymes to help carry out in many cellular reactions. 19. Many vital functions in the body are performed by inorganic molecules called minerals. 20. Calcium is needed in bone, iron is needed in blood, and muscles need potassium and sodium to function. (To function, bones need calcium, blood needs iron, and muscles need potassium and sodium.) 21. Carbohydrates, Fats, protein, vitamins and minerals are the five types nutrients.


 * 1) 69......Muscle and Skin Test.

(Complete sentences and no indefinite pronouns.) 1. Define digestion. 2. A nutrient is a substance .... 3. What is mechanical digestion? 4. What is chemical digestion? 5. Related to digestion, what is absorption? 6. Intracellular digestion occurs in ... 7. Extracellular digestion occurs... 8. What system transports nutrients to cells? 9. A ........... only has one opening. 10. A .......... has two openings. 11. .......... digestion is started by the teeth. 12. .......... digestion is started by saliva. 13. The liver and pancreas secrete fluids that... 14. Nutrients are absorb into the ... 15. The five types of nutrients in food are ... 16. Carbohydrates are made of ... 17. Sugars and starches are... 18. Fats and oils are compounds called... 19. Lipids are important for... 20. Proteins are formed from... 21. Digestion breaks proteins down into... 22. Most vitamins play a role in ... 23. Minerals are ... 24. The minerals in your diet com from... 25. Two functions of water are...
 * 1) 68......Digestion.....720......Due 5/25
 * 1) 67.....Extra Credit


 * 1) 66......Swamp Tiger Question


 * 1) 65......Bone Test

1. Muscle fibers that have their contracting units lined up across them look striated under a microscope. 2. Skeletal muscle is attached to bone, striated and voluntary. 3. Cardiac muscle is striated and involuntary. 4. Smooth muscle is found in organs and blood vessels, not striated and involuntary. 5. Skeletal muscle has more than one nucleus per cell. 6. Muscle only contract, so they only move in one direction. 7. Flexors bend joints and extensors muscles straighten joints. 8. Sarcomeres are the many, tiny, contracting units of muscle in which a thin filament slides past a thicker filament. 9. The integumentary system = skin and its glands, hair, and nails. 10. The skin functions to hold in fluids, keep out micro organisms, and block ultraviolet light. 11. Nerves that sense heat, cold, and pressure are in the dermis. 12. The epidermis is the thinnest and outer layer of the skin. 13. The outer cells of the epidermis are flat, dead, and water proof. 14. Melanin is a protects the skin from ultraviolet light. 15. The dermis contains many blood vessels, nerves, muscle, oil glands, and sweat glands. 16. The layer under the dermis is composed of mostly fat cells. 17. Tiny blood vessels in the dermis expand to allow heat in the blood to leave the body. 18. The evaporation of sweat cools the skin and removes heat from the body.
 * 1) 64......Muscles and Skin......Two column notes......Due 5/19

63...Bone Summary- Two columns...Due 5/18 1. Each bone of the supportive endoskeleton is a living organ. 2. Organs are combinations of tissues that perform one function. 3. The cells responsible for bone tissue formation are osteoblasts. 4. Tissues are a group of similar cells that perform one function. 5. The outer, denser material of bones is called compact bone. 6. The inner, less dense material of bone is called spongy bone. 7. Haversion canals contain a network of blood vessels and nerves. 8. A soft tissue that fills some spaces in bone is called marrow. 9. Blood cells are produce in red marrow tissue. 10. Fat cells in the centers of bones make up the yellow marrow. 11. The tough covering over bones is called the periosteum. 12. Cartilage is the cushioning and sliding material between bones. 13. Bones develop as osteoblasts deposit minerals in cartilage. 14. Bones are joined by ligements, which is a tough connective tissue. 15. Muscles are joined to bones by connective tissue called tendons. 16. A tissue in joints secretes a fluid that protect against friction. 17. Chronic inflammation of a joint is called arthritis. 18. Weight-bearing activities done over time as a young adult helps prevent osteoporosis. 19. What are the five joints types?

Make Up Assignment: Silk Spinners Paragraphs: Find a source of information on larvae, insects, and spiders that produce silk and write it down. If you are using the Internet, provide the URLs you use. 1. Write down 12 or more facts about Silk producing insects. (Spiders and larvae) 2. Compose two or three topic sentences that group or link the facts together in a logical way. 3. Write two or more paragraphs that contain eight or more of the facts. To receive credit, URLs must work, the facts must be listed, Topic sentences must be provided, and paragraphs must be listed. A good list of facts will get you half credit. Do a good job and you will earn extra credit.
 * 1) 62....Silk Spinner Facts..........Due 5/15

1. A tissue located in spongy bone that produce blood cells is... 2. A pigment that protects skin from the sun is... 3. Cephalization is... 4. The protective barrier between the body and the environment is... 5. Chronic inflammation of the joints is called... 6. A striated involuntary type of muscle that is found only in the heart is called... 7. Tissue that attaches muscle to bone is called... 8. The cells that produce bone are called... 9. The arms, legs, pelvis and shoulders make up the... 10. Involuntary muscle found in blood vessels and organs is called... 11. Vital organs are protected by the... 12. An internal hard skeleton is called... 13. The type of skeleton that molts is an... 14. What part of the skin contains sweat glands? 15. Tissue that connect the bones of the skeleton are... 16. What do hair and nails have in common? 17. What are Haversian canals?
 * 1) 61...Bones and Muscle Review...692-713

Use the previous six reading to answer these questions.

(Complete sentences /Complete subject or nouns /no pronouns) 1. What are the functions of skin? 2. What protein is found in skin? 3. What is one function of keratin? 4. The integumentary system consist of... 5. Three things skin protects you from are... 6. Three things skin can sense are... 7. The three layers of skin are... 8. What is the epidermis covered with? 9. Two things done by the dead skin cell layer are... 10. Collagen is found in the... 11. Collagen is a... 12. Melanin protects the skin from... 13. The dermis contains... 14. Sweat is a ... 15. Hair is made of... 16. A cuticle is... 17. What makes bruises dark? 18. What causes acne? 19. What causes athlete's foot? 20. What is skin cancer associated with? 21. How is it important to protect the skin? 22. What is the basis of test-tube skin? 23. What does test-tube skin lack?
 * 1) 60....Integumentary System...p.710...Due 5/13

FUNCTIONS OF COVERINGS: Your body is covered with a waterproof wrapper called skin. Skin protects and insulates your body. Amphibians have skin that stays moist and enables gas diffusion. A reptile's skin is composed of hard, dry scales. Birds have thin skin covered with feathers that insulate the body. For mammals that live in cold environments, such as white fox, fur is an important insulator. Polar bears have a thick layer of fat that keeps their bodies from losing hea below their fur. All of these coverings are suitable for specific niches. Though it differs, skin in all animals is made of the same protein-keratin. Keratin is insoluble in water so it forms a barrier that prevents the evaporation of water. The skin of an animal, whether it has fur, feathers, or scales, performs many of the same functions performed by human skin. HUMAN INTEGUMENTARY SYSTEM: The integumentary system covers your body and consists of the skin an( its glands, hair, and nails. The skin has surface area of 1.4 to 1.9 square meters and is the body's largest organ. An aver age person's skin weighs about 3 kg, more than twice as much as the brain. The integumentary system has several important functions. It protects the body by holding fluids in, an by keeping disease-causing microorganisms out. Pigments produced by your skin also protect you from the sun's harmful ultraviolet (UV) rays. Your skin makes vitamin D from sunlight and a lipid called cholesterol, which is found in the membranes of all animal cells. Millions of tiny nerve endings enable the skin to serve as a sense organ. The nerve endings sense heat, cold, and pressure. The skin has two main layers the epidermis and the dermis. If you have ever had a blister, you have seen the two layers separate. You can also see the layer of fat called the subcutaneous layer. This layer insulates the body and stores energy. Epidermis: The epidermis is the skin's outer layer. This skin layer is 10 to 30 cells thick-about as thick as this page. The epidermis is covered with tiny openings called pores. Sweat and oils secreted by the skin leave the body through the pores. If you were to look at the epidermis under a microscope lens, you would see a scaly surface. The top layer of the epidermis is made of flat, dead cells. These cells are full of keratin, the waterproof protein that helps keep bacteria from entering your body. Sebum, an oily substance produced by glands in the dermis, keeps the epidermis soft and flexible. The dead cells of the epidermis are constantly being shed. They are replaced by new cells from deeper within the epidermis. The entire layer of dead cells is replaced by the body about every 28 days. The thick inner layer of the skin is the dermis. The cells of the dermis make collagen, a protein that makes skin supple and strong. Collagen forms the ridges on your fingertips that make your fingerprints. It also forms ridges on the palms of your hands, your toes, and the soles of your feet. The ridges act as nonskid treads for your hands and feet. Specialized cells in the dermis produce melanin, the pigment that gives skin its color. Melanin protects the skin from the ultraviolet rays of the sun. Exposure to the sun increases the amount of melanin and darkens, or "tans," the skin. The dermis contains nerve endings, blood vessels, and hair follicles. The sebaceous glands, which produce sebum, are also located in the dermis. Sebaceous glands are usually attached to hair follicles. Sebum contains oil, which keeps hair from drying out. When sebaceous glands become blocked by sebum, a whitehead appears on the skin surface. When the sebum dries and darkens, it becomes a blackhead. If sebaceous glands become infected with bacteria, pimples and acne result. Sweat glands are also located in the dermis. If your body is too hot, sweat glands produce sweat-a fluid containing water, salt, and wastes. When sweat evaporates, it takes heat away from your body. Tiny blood vessels in the skin also help regulate your body temperature and store blood that can be used elsewhere in the body when needed. Hair follicles and sweat glands pass through the epidermis all the way to the surface of the skin. Hair and nails Hair and nails are made of dead epidermal cells. Each hair shaft grows from a root inside a hair follicle. The whole shaft of the hair, except f the living root, is made of dead cells similar to those in the top layer of t epidermis. Hair grows when cells in the root divide and push the rest of the shaft up and out of the follicle. Fingernails and toenails are solid plates of epidermal cells. Each type nail grows from a root that lies in a groove hidden by a fold of skin called the cuticle. The small white crescent that you see at the base of each nail is part of this growing area. CARING FOR YOUR SKIN Your skin is highly susceptible to injury. Have you watched small cuts on your skin heal, forming scabs that disappear from the edges inward as new skin forms? A bruise occurs when some of the skin's small blood vessels break. Blood from the broken vessels forms pools that look blue under the skin. Burns are a painful form of skin injury. A burn from a hot object may redden, blister, or even char the skin. Exposure to the sun can cause a burn regardless of your skin composition. Blistering and intense itching can result from contact with plants such as poison ivy or poison oak. Infectious organisms can cause diseases of the skin. A bacterial infection of the sebaceous glands causes acne. Bacteria can cause other skin infections, such as impetigo. Herpes viruses can cause sores to erupt in human skin. A fungus can cause the disease called athlete's foot. Skin cancer is a disease that results from the abnormal growth of skin cells. It is often associated with exposure to the sun and may appear as lumps, sores that do not heal, or unusual moles. Frequent baths or showers help to keep skin healthy. You should also eat a healthful diet with adequate B vitamins. Most importantly, you should protect your skin from overexposure to the sun by avoiding strong sunlight and wearing protective clothing and a sunscreen with a sun protection factor of at least 15. Inspect your skin on a regular basis and report any changes to your doctor. FRONTIERS IN BIOLOGY For people whose skin has been severely burned, a new technique has been developed in which burned areas can be healed with new skin that is nearly identical to the patient's original skin. The technique uses a product referred to as test-tube skin. Test-tube skin begins with protein fibers from cowhide and polysaccharides from shark cartilage. The material is made into a thin membrane that looks like wet tissue paper. Medical technicians seed the artificial membrane with cells from healthy areas of the patient's epidermis. Then the seeded membrane is laid over the burned area and covered with a silicone bandage to prevent it from drying out. In time, cells under the burned tissue divide and grow into new cells, forming the inner skin layer. Through repeated mitotic divisions, the cells seeded onto the surface of the membrane grow into a new outer skin. The new skin is just like the original skin, except that it has no sweat glands or hair follicles.

(Complete sentences /Complete subject or nouns /no pronouns) 1. .......... are bundles of muscle sell fibers covered by connective tissue. 2. A bundle is composed of... 3. Each muscle fiber is... 4. Muscle fibers are made of... 5. Each myofibril is made of... 6. Each..........has thick and thin filaments. 7. A sarcomere is... 8. Sarcomere are separated by... 9. A muscle cramp can occur when... 10. What happens in a severe muscle strain? 11. What is a muscle spasm? 12. Atrophy means... 13. How can muscle injury be avoided? 14. Describe a contracted muscle. p.708 15. Draw a contracted section of sarcomere. 16. Describe a relaxed muscle. 17. Draw a relaxed section of sarcomere. 18. Draw draw the three layers of skin. Include a sebaceous glans, hair follicle, sweat gland, sweat duct, nerve, vein, and artery in your drawing. CARING FOR YOUR MUSCLES If you have ever been stiff and sore after playing sports or doing other physical activity, you can appreciate how important it is to keep your muscular system healthy. Muscles need lots of exercise, but overworking a muscle may result in painful muscle cramps. There are several causes of muscle cramping. A cramp can occur when lactic acid-an end-product of anaerobic cellular respiration-is formed faster than it is removed. An injury or a nerve problem can also cause muscle cramps, so muscle soreness should always be treated in some way. Untreated problems can lead to greater injury. Overstretching a muscle can cause an injury called muscle strain. In a severe strain the muscles actually tear and bleed. Disorders resulting from improper nerve signals to the muscles can interfere with the normal functioning of muscles. For example, muscle spasms can occur when muscles involuntarily contract. Muscle spasms can cause discomfort or severe pain. When the nerve signals are lacking or interrupted, muscles can atrophy (waste away) or weaken. A disease called myasthenia gravis occurs when nerve signals fail to make muscles contract. A person with myasthenia gravis experiences a progressive weakening and tiring of the muscles. To maintain healthy muscles, exercise regularly. To avoid injury, warm up and stretch before exercising. To avoid overstressing particular muscles, vary your exercise. Aerobic exercises improve overall conditioning, and isometric exercises strengthen specific muscles. To build muscle, you must also eat well. Your body's muscles need adequate amounts of protein and minerals such as potassium and calcium.
 * 1) 59......Muscles 2......p. 708......Due 5/12

(Complete sentences /Complete subject or nouns /no pronouns) 1. Skeletal, smooth, and cardiac muscle are... 2. Skeletal muscle enables you to ... 3. Skeletal muscle are voluntary because... 4. What type of muscle is striated? 5. Striated means... 6. Skeletal muscle cells are different from most cells because... 7. Due to needing a lot of energy, muscle cells have... 8. Skeletal muscles contract and move .... 9. Smooth muscles are contained in ... 10. Smooth muscles are involuntary because... 11. Smooth muscles are controlled by... 12. Smooth muscles produce blood pressure because they regulate... 13. How is smooth muscle different from skeletal muscle? 14. Cardiac muscle is found only in the ... 15. Describe cardiac muscle... 16. Cardiac muscle is adapted to... 17. Why can a muscle only move a bone in one direction? 18. A flexor is a muscle that... 19. A extensor is a muscle that... 20. What is muscle tone? 21. Draw a flexor(bicep) and extensor(tricep) muscle on the three bones of the arm and label them. MUSCLE STRUCTURE AND FUNCTION Human muscles do many different jobs in the body. When you walk, chew, or dance, muscles move your skeleton. Other types of muscle keep your heart beating, move food through your digestive tract, and help your other internal organs function. Types of muscles: The human body contains three types of muscles. Each type is specialized to perform a different function. The type of muscle that enables you to move your arms, your legs, and other parts of your body is called skeletal muscle. Skeletal muscles are sometimes called voluntary muscles because they are under your conscious control. Skeletal muscle tissue is striated, which means it has narrow bands that can be seen with a microscope. Unlike most cells in the human body, skeletal muscle cells do not divide into two new cells during mitosis. The nuclei of skeletal muscle cells divide, but the cells do not. As a result, skeletal muscle cells grow into cells with many nuclei called muscle fibers. These cells also contain more mitochondria than most other types of cells. Remember the function of mitochondria. Why would the presence of more mitochondria be an advantage? Skeletal muscle fibers are arranged into bundles. The muscle bundles contract in response to nerve impulses. When a skeletal muscle contracts, it moves the part of the skeleton to which it is attached. Many of your internal organs contain smooth muscles. A smooth muscle is sometimes called an involuntary muscle because it is not under your conscious control. Smooth muscles are controlled partly by the nervous system and partly by the hormones of the endocrine system. Smooth muscles regulate the width of blood vessels and the contractions of the digestive system. They make your pupils contract when you are in bright sunlight. Smooth muscle tissue is not striated like skeletal muscle tissue. Another difference between these two types of muscles is that each smooth muscle cell contains only one nucleus. A third type of muscle tissue, cardiac muscle, is found only in the heart and nowhere else in the body. This type of muscle is striated and involuntary. Cardiac muscle tissue contracts and relaxes continuously throughout life. Unlike skeletal muscles, which can run low on oxygen and fatigue if worked repeatedly, cardiac muscle is adapted to work slowly and constantly In fact, a piece of heart muscle will continue beating for a time outside the body if it is placed in a warm saltwater solution similar to blood. Although cardiac muscle contracts without stimulation from the nervous system, the nervous system does affect the rate of the heartbeat. A skeletal muscle moves a bone by contracting, or shortening in length. The bone returns to its starting position when the muscle relaxes and returns to its former shape and length. Because a muscle exerts force only when it contracts, it can move a bone in only one direction. To provide motion in two directions, many skeletal muscles work in pairs. For example, for a joint such as an elbow or a knee to function, two muscles alternate contracting and relaxing. The muscle that bends a joint is called the flexor. The muscle that straightens a joint is called the extensor. Even when you are not consciously contracting your skeletal muscles, they are not completely relaxed. The skeletal muscles are always partially contracted. This slight contraction is called muscle tone. Muscle tone helps you maintain posture, keeps your skeleton aligned, and holds your internal organs in place.
 * 1) 58......Human Muscles......p. 706......Due 5/11

Make Up Assignment: Insect Paragraphs: Find a source of information on insects and write it down. If you are using the internet, provide the URLs you use. 1. Write down 12 or more facts about insects. 2. Compose two or three topic sentences that group or link the facts together in a logical way. 3. Write two or more paragraphs that contain eight or more of the facts. To receive credit, URLs must work, the facts must be listed, Topic sentences must be provided, and paragraphs must be listed.
 * 1) 57......Insect Video Questions..............5/8

1. Joints are classified as ... 2. What are the function and structure of bursa? 3. Ligaments are ... 4. Tendons are ... 5. A sprain is ... 6. Bursitis is ... 7. Arthritis is ... 8. Osteoporosis in the spine may result in... 9. Osteoporosis may be prevented by...and ... 10. Related to muscles, contract means to .... 11. Besides bones, muscles also move... 12. As muscles contract, they generate... 13. Muscle tissue consist of... 14. Appendages are operated by muscle... 15. In vertebrates, muscles are attached to... 16. Vertebrates can walk and run because... 17. Using figure 29.9, explain the four classes of joints. 18. From figure29.11, explain the four steps of bone healing. MOVEMENT The places where bones meet in the body are joints. Most of the body's joints allow movement between two bones; however, the structure of some joints prevents movement. Joints are classified as immovable, slightly movable, or freely movable. No movement takes place in immovable joints, such as those between the bones in an adult human's skull. Slightly movable joints, such as those between the vertebrae of the spine, allow only a small amount of movement. Freely movable joints allow the widest range of motion. Cushions of cartilage in joints keep the ends of the bones from rubbing against each other. Some freely movable joints are also lubricated and protected by fluid-filled sacs called bursae. Bursae absorb the impact of sudden pressure on a joint. Some bursae are present at birth, but others develop later in life in joints that are frequently used. The bones and muscles of freely movable joints are bound together by bands of tough connective tissues. Ligaments are connective tissues that join one bone to another. Tendons are connective tissues that attach muscles to bones. CARE OF YOUR SKELETON Although most of your skeletal system is tough and durable, it can still be injured. A sprain is an injury to the ligaments and tendons. Overuse of a shoulder or other freely movable joint can cause the fluid-filled bursa to swell, a painful condition called bursitis. An accident or fall may cause you to break, or fracture, a bone. A broken bone must have its ends aligned. Generally it must then be immobilized with a cast or splint. Healing takes place over time. Your skeletal system can also be affected by diseases. These include many forms of arthritis, a disease that causes joints to become inflamed and painful. Arthritis can result in a loss of joint function. Another disease, osteoporosis, causes brittle bones that break easily. In people who suffer from osteoporosis, the spine may degenerate, resulting in a noticeable hump in the back at the shoulder level or a shortening in height. Proper diet and a program of weight-bearing exercise begun early in life can help prevent the development of osteoporosis. Calcium and vitamin D are needed to grow strong bones. To maintain the health of your skeletal system, it is important to eat foods high in these two nutrients. Calcium-rich foods include dairy products, shellfish, leafy green vegetables, and tofu. Dairy products are fortified with vitamin D and the body can also make some of its own vitamin D, using sunlight. Weightbearing exercise, such as walking or running, also helps strengthen bones. FUNCTIONS OF MUSCLES Most types of animals are motile they move from place to place. Bones help support an organism and work with muscles to enable movement. How do muscles work? All muscles can contract and shorten. They are located where a contraction causes movement. For example, some muscles move body parts. This movement takes place because the muscles are attached to part of the skeleton. As the attached muscles shorten, they move the corresponding body part. In addition to making animals motile, muscles also move substances through the animals' bodies. The heart, an organ made of muscle, contracts repeatedly to pump blood. Muscle tissue in the walls of blood vessels contracts to affect blood flow throughout the body. Muscle tissue in the walls of an animal's digestive system contracts to move food through the body and wastes out of the body. As muscles contract, they use energy and generate heat. You may feel warm when you run or do hard physical work. Or you may shiver, stamp your feet, or wave your arms to stay warm while outside in cold weather. In these situations, your muscles produce heat as they work, warming your body. MUSCULAR SYSTEMS IN ANIMALS Some animals, such as sponges, do not have muscles. You may remember from Chapter 21 that sponges are sessile-they do not move. However, sponges use flagella to move large quantities of water through their saclike bodies as they filter out food particles. Most animals have specialized cells, tissues, and organs to make movement possible. Cnidarians, such as jellyfish, move using fibers that contract. Cells with bundles of microfilaments are arranged into these fibers. The contracting fibers push against fluid in the central body cavity, elongating the cnidarian and allowing it to move through the water. How do you think this level of organization compares with that of a human? Most animal phyla have true muscle tissue that consists of bundles of muscle cells. Some free-living flatworms have muscles in their body walls that allow them to swim through water with a wavelike motion, Roundworms have muscles that run the length of the body. When these muscles contract, the roundworm makes thrashing movements. The muscle system of an animal enables it to move about in one or more ways, such as crawling, burrowing, walking, jumping, running, swimming, or flying. Annelids such as earthworms have two sets of muscles. One set circles the body. Contracting circular muscles squeeze against the hydrostatic skeleton, extending the body. A second set of muscles runs the length of the body When these muscles contract, the body shortens and is pulled forward. Mollusks such as slugs and snails have a thick muscular foot used for gripping and creeping over surfaces. For example, a clam uses an elongated foot to move through wet sand. The tip of the foot extends, then widens to form an anchor. The rest of the foot then contracts, pulling the clam along. Arthropods such as lobsters and grasshoppers have muscles attached to a ,jointed exoskeleton. Muscle pairs operate each arthropod appendage. For example, a grasshopper's leg has one muscle that flexes the hind leg to get the grasshopper in position to jump. A second muscle forcefully extends the leg sending the grasshopper into the air. Vertebrates, such as fishes, birds, reptiles, amphibians, and mammals, have a system of muscles attached to the parts of an endoskeleton. Fishes have powerful swimming muscles that run along the sides of the body. Waves of muscular contraction move backward along the streamlined body, causing a wavelike motion that moves fishes forward. Reptiles, amphibians, and mammals can walk and run because pairs of opposing muscles move each limb. Snakes, which are limbless reptiles, use muscles in the body wall to push themselves along the ground. Birds use powerful chest muscles attached to a bladelike breastbone to raise and lower their wings for flight. In all vertebrates, muscles generate heat and help maintain posture.
 * 1) 56......Movement......p. 701......Due 5/7

Answer the questions or complete the sentences. Answer questions in complete sentences with the completer subject and no pronouns.
 * 1) 55......Skeletons......P.696......Due 5/6

1. Through the attachment of muscles, what do bones move like? 2. A hydrostatic skeleton is a ... 3. An exoskeleton is a ... 4. What is molting? 5. Describe the skeletons of vertebrates. 6. Of what does the axial skeleton consist? p.698 7. The axial skeleton protects what vital organs? 8. Of what does the appendicular skeleton consists? 9. Why does the body need calcium? 10. What minerals make bone hard? 11. Bones are covered by ... 12. Spongy bone is found in ... 13. Compact bone is found in ... 14. What does red marrow produce? 15. Yellow marrow is made up of ... 16. Haversian canals are ... 17. The cells in bones are called ... 18. The structure of a bone is related to its ... 19. Fetal skeletons are mostly made of ... 20. What materials acts as cushions between bones? FUNCTIONS OF SKELETONS Every living organism needs support to keep its shape. Unicellular organisms get all the support they need from their cell membranes and cytoskeletons. Humans and other large, multicellular animals need a rigid structure called a skeleton for support. The skeleton is a framework for the body. Like the steel girders that form the framework of a tall building, the skeleton determines an organism's overall shape. In addition to supporting the body, a skeleton performs other functions, such as protecting the internal organs and allowing movement. For example, a mammal's hard, bony skull protects the animal's soft, fragile brain. A mammal can walk because muscles attached to long leg bones contract and cause the bones to move like a lever. Mammal bones also contain a store of minerals, such as calcium and phosphorus, that can be used by the body when needed. Soft tissue on the inside of the bones manufactures blood cells. THREE TYPES OF SKELETONS An animal's skeleton should provide body support, protect the internal organs, and allow for movement. Over time, different groups of animals have evolved with three distinct types of skeletons. Animals such as cnidarians, flatworms, nematodes, and annelids have a hydrostatic skeleton. A hydrostatic skeleton is a support system consisting of a body compartment filled with fluid under pressure. Unlike human skeletons, hydrostatic skeletons do not contain any hard structures such as bones. Either contractile cells or muscles surround the fluid-filled compartment. When contraction occurs, the compartment elongates and the animal moves forward. This type of skeleton provides adequate support for some animals that live in water and some animals that live in soil, and cushions the animals' internal organs. Arthropods, such as crabs and insects, have an exoskeleton. An exoskeleton is a hard covering on the outside of a body that provides both support and protection. The exoskeletons of arthropods are composed of a layer of nonliving material called chitin. The chitin layer covers the entire body, forming a jointed encasement somewhat like a suit of armor. Because exoskeletons cannot grow, animals with exoskeletons must molt, or shed their protective covering, to grow. An exoskeleton provides excellent body support and protection for some animals living in water or on land. Muscles attached to the inside of the exoskeleton can contract to move an animal's appendages. Animals with this type of skeleton can move around freely. They may swim, crawl, walk, or fly. Vertebrates, such as humans and other mammals, fishes, and birds, have skeletons made of bone and cartilage located inside the body An internal hard skeleton is called an endoskeleton. An endoskeleton does not protect all soft body tissues as well as an exoskeleton does, but an endoskeleton does allow for freer movement and greater growth. In contrast to a nonliving exoskeleton, an endoskeleton is a living framework that can grow along with the animal. THE SKELETON The human skeleton is made of bones, the joints where bones meet, and the connective tissues that hold the bones together. There are 206 bones in the human skeleton. Each bone has a size and shape that suits its particular function. Like the skeletons of other vertebrates, the human skeleton can be divided into two parts: the axial and the appendicular skeletons. The skull, vertebral column, and rib cage make up the axial skeleton. The bones of the axial skeleton protect vital organs such as the brain, heart, and lungs. The vertebral column, made of a stack of vertebrae, holds the body upright and allows it to bend and twist into many positions. Soft tissues inside the vertebrae, ribs, and sternum make red and white blood cells. The arm and leg bones, with the bones of the pelvis and shoulder areas. form the appendicular skeleton. The arm bones and leg bones move like levers, allowing you to walk, run, obtain food, and perform all the activities of a mobile land animal. Soft tissues in the pelvis make red and white blood cells. Calcium is stored in the thick knobs at the ends of long bones. Calcium hardens bone and is an essential element needed by the body for muscle contraction and nerve impulse transmission. FROM BONES TO BONE CELLS If you have ever struck a piece of bone while cutting into a steak, lambchop, or shortrib, you know that bones are hard and fairly rigid. Bones get their hard consistency from minerals, especially calcium and phosphorus. Because bone is so hard, you may think it is not alive. However, bone is living :issue made of cells and minerals. Bones are covered by a membrane called the periosteum. Branching through the periosteum are small blood vessels. Blood moving through these vessels carries nutrients to the bone and takes wastes away. There is no periosteum at the ends of bones. Bone tissue may be either spongy or compact. Spongy bone, tissue with many spaces, is found in the ends of long bones and in the middle part of short, flat bones. Compact bone is very dense. Its density provides support. Compact bone is found in the shafts of long bones such as the upper arm (humerus) and upper leg (femur). A soft tissue that fills some spaces in bone is called marrow. In the micrograph of spongy bone, in Figure 29.7, you can see the large spaces that contain red bone marrow. Red bone marrow is a material that produces blood cells. Another type of bone marrow, yellow bone marrow, is mostly made up of fat cells. Yellow bone marrow is most often found in the cavities within the shafts of the long bones. Notice the circular channels in the compact bone. These channels are called Haversian canals and are spaces through which nerves and blood vessels pass. Because of the Haversian canals, compact bones are lighter in mass than they would be if they were solid. Scattered throughout the bone are cells called osteoblasts. Osteoblasts make the new bone cells needed for growth and repair. Found in both compact and spongy bone, osteoblasts are concentrated on the inner surface of the periosteum. The structure of a bone is related to its function. The bones of the skeletal system support the body and give it shape. In addition to support, bones also serve the functions. Bone is continuously replaced throughout life, A fetal skeleton is mostly made of cartilage, a tough but flexible connective tissue. By the time a baby is born, much of the cartilage in its arms and legs has been replaced by bone. As the baby grows and develops, most of the remaining cartilage, is gradually replaced with heavier, harder bone. The skeletal system continues to replace cartilage with bone until a person is about 25 years old. Some cartilage is always present in the skeletal system. For example, your outer ears, the tip of your nose, and the cushions between the vertebrae of your spine are all made of cartilage. Gently bend your nose and ears. As you can see, cartilage makes these parts flexible.

1. The circulatory system's function is to ... 2. What is the circulatory system comprised of? 3. What are the four functions of the skeletal system? 4. What is the skeletal system comprised of ? 5. The integumentary system's function is to ... 6. What is the integumentary system comprised of? 7. What are the two functions of the respiratory system? 8. What is the respiratory system comprised of? 9. The excretory system's function is to ... 10. What is the excretory system comprised of? 11. What are the two functions of the nervous system? 12. What is the nervous system comprised of? 13. The three functions of the digestive system are ... 14. What is the digestive system comprised of? 15. The function of the immunes system is to ... 16. What is the immune system comprised of? 17. The function of the lymphatic system is to ... 18. What does the lymphatic system filter out of the fluid it returns to the circulatory system? 19. What is the the lymphatic system made up of? 20. Why do some internal organs contain muscle cells? 21. The function of the endocrine system is to ... 22. What is the endocrine system comprised of? 23. What system functions to produce offspring? 24. Explain what an organ is. 25. Explain what an organ system is. __Twelve Body Systems Summary__
 * 1) 54......Twelve Body System......P. 694......Due 5/5

The circulatory system transports essential substances throughout the body. This system includes the heart, the network of blood vessels, and blood.

The respiratory system is made of a network of breathing passages and the lungs. These organs take in oxygen from the air and release carbon dioxide.

The excretory system removes wastes from the body. It includes the kidneys and the bladder. The skin and the lungs are sometimes considered part of the excretory system.

The skeletal system-the body's framework-is made of bones, joints, and cartilage. It helps with movement, stores minerals, makes blood cells, and protects internal organs.

The integumentary system includes the skin, hair, nails, and the glands in the skin. This system forms a waterproof protective barrier between a body and its environment.

The nervous system detects changes in the environment and signals responses. It includes the brain, the spinal cord, and the nerves that transmit information throughout the body.

The digestive system takes in and breaks down food and absorbs nutrients. It includes the mouth, esophagus, stomach, intestines, liver, gallbladder, and pancreas.

The immune system defends the body against infectious agents. This system includes bone marrow and white blood cells, and organs such as lymph nodes and thymus.

The lymphatic system returns fluid from spaces between cells to the circulatory system. It also filters bacteria and particles out of the fluid. This system is made of a network of vessels and lymph nodes, as well as organs such as the spleen, tonsils, and appendix.

The endocrine system secretes chemicals called hormones. This system includes the thyroid, the pituitary, and the adrenal ,lands.

The reproductive system enables the body to produce offspring. This system includes some endocrine glands as well as the reproductive organs.

When muscles work with bones, they move parts of the body-including hands fingers, legs, neck, and head. Muscles in internal organs move substances in the organs.

1. What are tissues? Tissues are ... 2. The four types of tissues are ... 3. The five functions of connective tissue are ... 4. Five examples of connective tissue are ... 5. What is muscle tissue made of? 6. Two organs that contain muscle tissue are ... 7. What does epithelial tissue do? 8. The epithelial tissue that covers the body is ... 9. What is a gland? A gland is ... 10. Three human glands are ... 11. What is the function of a neuron? 12. What are the functions of glial cells? 13. A structure made of more than one tissue is called an ... 14. What tissues make up the stomach? 15. What is an organ system comprised of? 16. Anterior means ... 17. Posterior means ... 18. Ventral means ... 19. Dorsal means ... 20. Copy figure 29.2 on page 693. __Body Systems__ LEVELS OF ORGANIZATION You are one person, one organism. But the body you have is made of billions of individual cells. Although each cell performs basic life functions, such as using energy and excreting wastes, it is only a small part of the highly organized structure that is your body. Groups of cells with similar structure and function are called tissues. The cells in a tissue are held together by a nonliving matrix or a sticky coating on the outside of the cells. Most animals have four main types of tissues: connective, muscle, epithelial, and nervous tissue. Each type of tissue has II a specialized function. Connective tissue joins together body structures, providing protection and support. Connective tissue can store or transport materials. It can be hard, soft, or liquid. Bones, tendons, cartilage, fat, and blood are examples of connective tissue. Muscle tissue is made of cells that contract in response to signals from the spinal cord and brain. All body movement, including that of internal organs, is carried out by muscle tissue. Muscle tissue makes it possible for you to breathe, talk, and move your arms and legs. Many internal organs, such as the heart and stomach, contain muscle tissue. Epithelial tissue covers the body and its organs. The skin is an organ that contains epithelial tissue. Inside the body, epithelial tissue lines organs and blood vessels. Some types of epithelial tissue form glands-structures that release chemicals. Human glands include sweat glands, mucous glands, and digestive glands. Nervous tissue, composed of two of cells, carries information the body. One type of cell, a neuron, conducts signals in the form of electrical impulses throughout the body. The other type of cell-a glial cell-supports, protects, and coordinates the neurons. In most animals, tissues are organized into functional units called organs. The stomach is a saclike organ. It is made of epithelial, muscle, nervous, and connective tissue. Groups of organs that work together to perform specific functions for the organism comprise organ systems. The stomach, large intestine, and small intestine together form a major part of the digestive system. BASIC BODY PLAN The left and right sides of your body are almost mirror images. You may recall that other vertebrates and some invertebrates show this pattern called bilateral symmetry. Although the sides of your body are almost mirror images, they are not identical. You can find a few differences by studying the sides of your face in a mirror. Inside the body, many organs and organ systems do not show complete bilateral symmetry. For example, the two sides of the stomach and digestive system are quite different. The locations on the bodies of animals with bilateral symmetry can be described by four terms-anterior (top), posterior (bottom), ventral (front), and dorsal (back). Consider these four parts of your body. Like other animals with bilateral symmetry, humans have a high degree of cephalization (sef-uh-luh-ZAY shun). Cephalization means that the sense organs and the structures that control the body are located in its anterior part. For example, your eyes, ears, nose, and mouth are all sense organs located in your head. The internal organs are located within two large spaces called the ventral and dorsal body cavities. The body cavities develop from the coelom. You may recall from Chapter 22 that the coelom is a body cavity that when formed is completely lined with mesoderm. When the body grows or moves, internal organs are stably contained within the body cavities. This explains why your heart does not move around when you exercise!
 * 1) 53......Body Systems......P. 692......Due 5/4

Alternative Assignment: Google the following. Give three facts about spring tails insects. Give three facts about snails. Give three facts about centipedes. Give three facts about millipedes. Give three facts about earthworms. Give three facts about scorpions.
 * 1) 52.....”Life in the Undergrowth” Movie Questions...........5/1

1. What does genetic engineering refer to? 2. What is a restriction enzyme? 3. What causes different DNA pieces to move different distances in gel electrophoresis? 4. What is a DNA fingerprint? 5. What is recombinant DNA? 6. Why would specific human genes be put in bacteria? 7. What are two vectors used by genetic engineers? 8. What is used to cut a gene out of a chromosome? 9. What is a transgenic organism? 10. What produces the milk stimulating hormone (BGH) that is injected into milk cows? 11. What is the most commonly genetically engineered organism? 12. What does gene therapy involve? 13. What is a major stumbling block of gene therapy? 14. How is bacteria produced insulin better than animal sources? 15. How can DNA fingerprints be used? 16. What is the dark side of biotechnology? 17. How may genetic engineering be used unethically?
 * 1) 51......Genetic Engineering......P. 209......Due 4/30

1. List seven illnesses caused by viruses. 2. What is a virus? 3. What invention enabled the discovery of viruses? 4. What is the only thing that viruses can do? 5. What does a host cell do for a virus? 6. What is the two ways a virus can act? 7. What is an active virus? 8. What is a latent virus? 9. What causes a latent virus to go active? 10. What is a cold sore a sign of? 11. When a cold sore heals, what is the virus doing? 12. What are four groups of organisms that viruses infect? 13. What virus has a broad range of hosts? 14. What is one way a virus can reach a host? 15. When infecting, what does a virus do first? 16. Why do most viruses only attack one kind of host cell? 17. What are vaccines made of? 18. From what did Jenner prepare his vaccine? 19. What kind medication is not effective against viruses? 20. What do interferons do? 21.Why is the use of antiviral drugs limited? 22. Draw and label Figure 15 on page 53
 * 1) 50......Viruses Recap Page 52............4/29

1. What does virus mean in Latin? 2. What did the crystals isolated Stanley consist of? 3. In what three ways are viruses classified? 4. What determines the shape of a virus? 5. What four groups of host do viruses infect? 6. What is required for a virus's nucleic acid to enter a cell? 7. What is “retro” about a retrovirus? 8. What does reverse transcriptase do? 9. What kind of viruses are tumor producing viruses? 10. What is a viroid? 11. What is a prion? 12. What causes mad-cow disease? 13. What do viruses do that cause diseases? 14. What killed more people than World War I? 15. What are two ways viruses are spread? 16. What medicine can't cure virus infections? 17. What is a vaccination? 18. How could viruses be useful to help humans? 19. How could viruses be useful in agriculture?
 * 1) 49......Viruses............4/28

1. What are viruses made up of? 2. What three things do viruses lack? 3. Is a virus a cell? 4. What are the two parts of a virus? 5. What is a capsid? 6. What do viruses use RNA and DNA for? 7. What does a viruses envelope do? 8. What do viruses require to replicate? 9. What do host cells do for a virus? 10. What is the lytic cycle? 11. What occurs when a host cell breaks apart? 12. What is the lysogenic cycle? 13. What happens to viral DNA during the lysogenic cycle? 14. What happens when herpes cold sore virus switches from the lysogenic to lytic cycle? 15. Write the words of Figure 14.3.
 * 1) 48......Viruses

Alternative assignment: List 25 Facts about Crocodiles and Alligators.
 * 1) 47......Crocodiles and Alligators Video

Genetics and Probabilities: 1. A Punnett square organizes information in order to make genetic predictions. 2. Pedigrees are used to trace the history of traits among relatives. 3. When heterozygous offspring show a phenotype that is in between two homozygous parents, this is incomplete dominance. 4. When both alleles in heterozygous offspring are fully expressed, this is codominance. 5. A trait controlled by two or more genes is called a polygenic.
 * 1) 46 Two Column Notes

Inheriting Traits: 1. Heredity is the passing of traits from parents to offspring. 2. Genetics is the study of how traits are inherited through the interaction of alleles. 3. The different forms of a trait that make up a gene pair are called alleles. 4. An organism with two alleles that are the same is called homozygous. 5. The phenotype of an organism is the outward characteristics that result from the interaction or expression of their alleles for a trait.
 * 1) 45......Two Column notes............4/20

Copy the question and answer it or write the answer in a complete sentence using no pronouns. 1. What is intermediate inheritance? 2. In intermediate inheritance, what does the phenotypes of heterozygous offspring show? 3. How many forms of incomplete inheritance are there? 4. What is incomplete dominance? 5. Explain incomplete dominance using an example? 6. What is codominance? 7. Explain what makes the different blood types. 8. How are the different alleles for each bloood type indicated? 9. Copy figure 6.18 (blood type genotypes and phenotypes) 10. What are polygenic traits? 11. What three differences indicate eye color is polygenic? 12. When are genes said to have multiple alleles? 13. When is a gene pleiotropy? 14. What is sickle-cell disorder? 15. Why is sicle-cell trait considered pleiotropy? 16. Explain three examples of the environmental effects on genes. 17. What suggests genes can affect behavior?
 * 1) 44...... Intermediate inheritance............4/16

Reading INTERMEDIATE INHERITANCE For the pea plant traits that Mendel studied, one allele was always dominant over the other. However, traits Kith two distinct forms are rare in nature. Many genes do not have purely dominant and recessive alleles. Instead, these genes show a form of intermediate inheritance. In intermediate inheritance, the heterozygous offspring have a trait that is not exactly like the trait of either purebred parent. The phenotype of the heterozygous offspring shows the effects of more than one allele. You will now read about three forms of intermediate inheritance: incomplete dominance, codominance, and polygenic inheritance. When two different alleles for the same trait combine, but neither allele "wins" expression over the other, the offspring have a form of intermediate inheritance called incomplete dominance. In incomplete dominance, heterozygous offspring show a phenotype that is in between the phenotypes of the two homozygous parents. Neither allele is fully expressed. One example of incomplete dominance is flower color in snapdragons. If a snapdragon plant with red flowers is crossed with a white-flowered snapdragon plant, the offspring will have pink flowers. The alleles have not blended to make pink alleles. The red and white alleles remain separate in the snapdragon cells. Only the phenotype is intermediate, giving the appearance of pink flowers. Half the gametes of a pink snapdragon plant carry the allele for red flowers, and half carry the allele for white flowers. Incomplete dominance is also responsible for the coat colors of many animals. Roan cows, whose coats are primarily red with white hairs, are offspring of red cows and white cows. A palomino-a creamy-golden horse with a pale mane and tail-is the offspring of a chestnut-colored horse and a white horse. An example of a human trait that shows incomplete dominance is hypercholesterolemia. People with this disorder have too much ("hyper-") cholesterol in their blood. Cholesterol is a steroid produced by our bodies and used to make and repair cell membranes. People with normal cholesterol levels have the homozygous dominant genotype (HH). People with this genotype generally can maintain healthy blood cholesterol levels with a low-fat diet and exercise. About one in 500 people are heterozygous (Hh) for the trait, and their cholesterol levels are twice as high as normal. Diet, exercise, and medical treatments can help to reduce their cholesterol levels. About one in a million people are homozygous recessive (hh) for the trait. Their cholesterol levels are about five times greater than normal. This rare homozygous recessive condition is very serious-it has even caused heart attacks in two-year-old children. As you just learned, incomplete dominance occurs when two alleles are partially expressed and the offspring have a phenotype that is intermediate, or in between, the two parent phenotypes. In codominance, both alleles in the heterozygote express themselves fully. Because both of the alleles are fully expressed, both alleles are equally emphasized in the notation. An example of a codominant trait in humans is blood type. The letters A and B that identify blood types refer the two different carbohydrates t coat the surface of red blood cells. If you have type A blood, you have type A carbohydrate on your red d cells. If you have type B blood, have type B carbohydrate on your blood cells. And if you have blood AB, you have both carbohydrate s. People who have neither carbohydrate on their red blood cells have type o. These alleles are represented by an L and a superscript A or B to indicate whether the allele codes for type A or type B blood. The two alleles are IA and r. If you received the blood type A allele (IA) from one parent and the blood type B allele (IB) from the other, your genotype is IAIB, and your phenotype type is AB blood. You will find out more about blood types later in this section. Most traits are affected by more than one gene. A trait controlled by two or more genes is called a polygenic trait (the prefix; "poly-" means "many"). Your eye color is an example of a polygenic trait. The tone, amount, and distribution of the pigment melanin all play a role in determining eye color. These characteristics are determined by many different gene pairs. And, like Mendel's pea plant genes, each gene pair for eye color might be inherited independently. Human skin color is also a polygenic trait. Many genes control the amount of the melanin in the skin. Many alleles and traits Most genes have more than two alleles. If three or more alleles are found in the population, we say these genes have multiple alleles. Human blood type genes are an example of a codominant trait and of a trait with multiple alleles. Blood types are phenotypes that can be produced by three different alleles-IA, IB, and i. Each person has only two of these alleles, one from each parent. As you already learned, the alleles for A and B blood types are codominant. If you have blood type 0, then you have neither type A nor type B carbohydrates coating your red blood cells. 0 blood type is recessive, so the allele for 0 blood type is i. Thus, there are four blood types-A, B, AB, and 0-and three blood type alleles-IA, IB, and i. Figure 6.18 shows the phenotypes and genotypes for blood. Another variation on the simple patterns of inheritance seen in Mendel's pea plants is called pleiotropy. Pleiotropy occurs when a single gene affects more than one trait. Sickle-cell disease is an example of pleiotropy in humans. The allele that causes sickle-cell disease affects the shape of red blood cells. As you can see in Figure 6.19, blood cells in people with sickle-cell disease have a bent, or sickled, shape. The sickled cells do not flow well through the body and tend to clump together, blocking and damaging parts of the circulatory system. Damage to the circulatory system can have many phenotypic results. People with sickle-cell disease can experience weakness, anemia, brain damage, spleen damage and heart damage. Because of its numerous effects on the body, this allele is an example of pleiotropy. ENVIRONMENTAL EFFECTS As you have discovered, many factors-including the activity of other genes-can influence the way a gene is expressed. Genes can also be affected by the environment-both the external environment and the environment inside an organism. In fact, phenotype is a combination of genetic and environmental influences. Climate conditions are an outside environmental factor that can influence the expression of alleles. An unusual effect of temperature is seen in the Himalayan rabbit. This rabbit is normally covered with white fur, whereas its ears, nose, and feet are black. This pattern occurs because most of the rabbit's body is generally warmer than its extremities. Body temperature affects the expression of genes that code for fur color. When researchers remove a patch of hair from the body and cool the skin as new fur grows back, the new fur is black. When they shave hair from the feet or ears and keep those areas warm, the fur that grows back is white. Environmental temperature also affects wing coloration patterns of the western white butterfly, found in the west of North America. These butterflies need their body temperature to be between 28°C and 40°C to take off in flight. Researchers have found that butterflies reaching adulthood in the spring exhibit darker wing coloration patterns than butterflies that mature in the summer. As you may know, dark colors absorb more heat. As a result of their darker wing patterns, the butterflies that live during the cooler spring weather will be able to reach a warm enough temperature to fly. In this case, the expression of the wing color genes is affected by day length, which varies from season to season. Another example of environmental influence on gene expression is flower color in hydrangeas. Hydrangea flowers are either blue or pink, depending on soil acidity If the soil is rather acidic, the hydrangeas have blue flowers. If the soil is neutral or somewhat basic, then the blooms are pink. Changes in the social environment of an organism can also affect gene expression. The Japanese goby fish can change its sex back and forth in response to changes in its social environment. If a large male goby leaves a population, a female goby will become male. If another large male enters that goby population, this new male turns back into a female. Gene expression can be influenced by the environment inside an organism's body. Although human height is determined by a form of polygenic inheritance, it is also affected by the nutrients in your diet. As you read earlier in this chapter, shyness can also be affected by genes. But, as individuals mature, the effect of genes on shyness diminishes, and the effect of the environment increases. It is important to realize that the inheritance of shyness, height, and many other human traits is affected by genetics and also by the environment. In Chapter 8, you will learn more about effects of the environment on gene expression, particularly in the development of cancer.

The genetics of behavior How can you determine if the inheritance of a trait is affected more by genetics or by the environment? This question-commonly expressed as "nature or nurture?"-is difficult to answer, especially for human traits. To find answers, some scientists study identical twins-people with the same genes-that have been separated at birth. Twins separated at birth or at a very young age and brought up by different families have different environments. These twins offer scientists an opportunity to study genetic and environmental influences. Twin studies have shown some surprising results. For example, when one set of identical twin sisters met for the first time, each sister was wearing seven rings, three bracelets and a watch. Another set of identical twins were both named Jim by their adoptive parents. Both had dogs named Toy, married women named Linda, and named their sons James. Surveys of reunited twins found that, in addition to their shared habits, they also shared many opinions. Although studies of identical twins separated at birth suggest some links between heredity and behavior, identical twins do not lead identical lives. Despite having similarities that could be explained by their identical genes, these separated twins also exhibited differences as a result of the different environments in which each grew up. This fascinating mix of similarities and differences gives researchers a unique opportunity to explore the effects of heredity and environment.


 * 1) 43......Genetic Disorders............4/15



Copy this Pedigree on the top half of your paper. Answer questions in complete sentences with no pronouns.

1. (write) Pedigrees can be used to determine a parents genotype.

2. Label the first row in the pedigree “I. Grandparents.” Label the second row “II. Parents.” Label the third row “III. Children.”

3. Label each individual in the pedigree with their phenotype.

4. Does deafness skip a generation or is someone deaf in every generation?

5. What is the genotype of an individual with deafness?

6. What are the two possible genotypes for hearing people in this pedigree?

7. Is any of the Grandparent generation deaf? Is all of the Child generation deaf or not?

8. As evidenced by the answers above, Is the allele for deafness dominant or recessive and how do you know?

9. The three genotypes are homozygous dominant, homozygous recessive, and heterozygous. Write the genotypes of individual numbered 6, 10, and 14 under their circle or square.

10. Look at the offspring on number 6 and 7. The fact that number 7 had deaf offspring means she has a deaf allele. Write the genotype of number 7 under her circle.

11. Children numbered 8, 9, 11, 12, & 13 must get their hearing allele from their mother and their father has only non hearing alleles to provide. Write the genotypes for the rest of the III generation under their circles or squares.

12. Look at the grandparents numbered 1 and 2. Use the fact that they have deaf off­spring to write their genotypes under their circle or Square.

12. Use a Punnett square to figure out the probability of individual number 5 being homozygous dominant verses heterozygous.

13. What are the possible genotypes for the grandparents numbered 3 and 4.

42......Punnett Squares 2............4/14 Answer the following in complete sentences using no pronouns. 1. List the terms for the three genotypes. 2. If a parent's alleles were represented with the letters PP on a Punnett Square, what would be its genotype? 3. If a parent's alleles were represented with the letters pp on a Punnett Square, what would be its genotype.? 4. If an individual's alleles were represented with the letters Pp on a Punnett Square, what would be it genotype? 5. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers, what letters would be used to represent the genotype of a homozygous dominant individual on a Punnett square? 6. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers, what letters would be used to represent the genotype of a homozygous recessive individual on a Punnett square? 7. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers, what letters would be used to represent the genotype of a heterozygous individual on a Punnett square? 8. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers, what would be the phenotype of the flowers be of a plant with the alleles represented by PP? 9. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers , what would be the phenotype of the flowers be of a plant with the alleles represented by Pp? 10. If P represents an allele for the dominant trait of purple flowers and p represents the recessive allele of white flowers, what would be the phenotype of the flowers be of a plant with the alleles represented by pp? 11. Make a Punnett square for predicting the outcome of a cross between a homozygous dominant plant with purple flowers and a homozygous recessive plant with white flowers. 12. Use #11's Punnett square to give the genotype(s) and probable percentage for each genotype of offspring that would likely be produced. 13. Use #11's Punnett square to give the phenotype(s) and probable percentage for each phenotype of offspring that would likely be produced. 14. Make a Punnett square for predicting the outcome of a cross between two heterozygous plants with purple flowers. 15, Use #14's Punnett square to give the genotype(s) and probable percentage for each genotype of offspring that would likely be produced. 16. Use #14's Punnett square to give the phenotype(s) and probable percentage for each phenotype of offspring that would likely be produced. 17. Test crosses are used to tell if an individual is homozygous dominant or heterozygous. What letters represent unknown individual's alleles and what genotype would the unknown parent be for the Punnett square on the board? 18. Test crosses are used to tell if an individual is homozygous dominant or heterozygous. What letters represent unknown individual's alleles and what genotype would the unknown parent be for the Punnett square on the board?

41......Punnett Squares.............4/14 Copy: 1. Punnett squares are used to predict the genotypes and phenotypes of offspring in breeding experiments. 2. Punnett squares show probabilities and not the actual results of breeding experiments. 3. In a monohybrid cross, a Punnett square can be used to study one trait. 4. In a dihybrid cross, a Punnett square can be used to study two traits. 5. By comparing the results of a cross to the probabilities show by Punnett squares the genotypes of the parents can be determined. 6. A test cross is when a parent with an unknown genotype is crossed with a homozygous recessive individual. 7. If all the offspring from a test cross show the dominant trait, then the parent was homozygous dominant. 8. If half the offspring from a test cross show the dominant trait and the other half show the recessive trait, then the parent was a hybrid. Answer: 9. Make a Punnett square for the cross of a homozygous dominant parent with a homozygous recessive parent. This would be like Mendel's parent or P generation and the offspring would be the F1 generation. 10. What is the ratio of genotypes of the above cross? 11. What is the ratio of phenotypes of the above cross? 12. Make a Punnet square for the cross of two of the offspring in the above cross. This would be like crossing Mendel's F1 generation to produce the F2 generation. 13. What is the ratio of genotypes of F2 generation? 14. What is the ratio of phenotypes of the F2 generation? Do: 15. Copy all of figure 6.10 on page 141 in the wolf book.

Copy the following facts: 1. Mendel raised pea plants and never observed a blending of contrasting forms of a trait in their offspring. 2. To stop self pollination, Mendel snipped the pollen producing structures off the flowers. (Anthers) 3. To control cross pollination between flowers, Mendel transferred pollen with a paintbrush. 4. Mendel called the first plants he crossed the P generation. 5. The genotypes of the plants used for this cross was homozygous dominant and homozygous recessive. 6. Mendel called the offspring from the first cross the F1 generation. 7. Mendel observed that crossing purebred plants with contrasting phenotypes resulted in offspring with only one phenotypes 8. The genotype of the F1 generation is heterozygous and Mendel called them hybrids. 9. Mendel then let the plants of the F1 generation self pollinate to produce a second group of offspring. 10. Mendel called the offspring from this second cross the F2 generation. 11. Mendel crossed plants with seven different contrasting traits and found that the F1 generation express only the dominant trait, but the F2 generation expressed both the dominant and recessive traits in a 3:1 ratio every time. (75% to 25%) 13. Because the recessive trait disappeared in the F1 generation and then reappeared in the F2 generation, Mendel reasoned that traits are controlled by a pair of factors and an offspring receives one from each parent. 14. Today we know that most organism have two copies of every gene and chromosome, one from each parent. 15. Today we know that the factors that control a trait are genes and different forms of genes are called alleles, where one can be dominant and the other recessive.
 * 1) 40......Mendel Experiment Redo............4/3

Answer the following questions in complete sentences without using pronouns. Use the list of facts below. 1. What observation of Mendel's didn't agree with the “blending hypothesis?” 2. Why did Mendel cut the male parts off the flowers of his plants? 3. Why did Mendel transfer pollen between flowers with a toothbrush? 4. What was the P generation? The P generation is ...... 5. Describe the types of pea plants used for the P generation. Use some of the terms above in this description. 6. Make a Punnett square for the P generation. A cross of a homozygous dominant plant with a homozygous recessive plant. 7. What was the F1 generation? 8. What observation did Mendel make of the F1 generation's phenotype? Mendel observed .......... 9. What was the genotype of the F1 generation? The genotype was ........... 10. Make a Punnett square for F1 generation. A cross of two hybrid plants. 11. How was the F2 generation produced? 12. How many phenotypes were observed in the F2 generation? Use the word phenotype in your answer. 13. What did Mendel conclude from the reappearance of the reappearance of the recessive trait in the F2 generation? 14. How are traits related to genes? 15. How are genes related to alleles?
 * __Incomplete sentences__ or __the use of pronouns__ will result in __half credit__.**

**Two column definitions**: Copy it in one column and rewrite it in your own words in the second column. 1. A gene is a sequence of bases on a chromosomes that code for a trait. 2. Alleles are the different forms of a trait/gene and they can be dominant or recessive. 3. A dominant allele is a form of a gene that is fully expressed when two different alleles are present. 4. A recessive allele is a form of a gene that is not expressed when paired with the dominant allele. 5. An organism in which the two alleles in a gene pair are identical is called homozygous. (Purebreds) 6. An organism in which the two alleles in a gene pair are different is called heterozygous. (Hybrids) 7. Purebreds receive identical forms of an allele from both their parents. (Homozygous) 8. Hybrids receive different forms of an allele from each parent. (Heterozygous) 9. Genotype is the genetic make up of an organism, that can be homozygous or heterozygous. 10. Phenotype is the outward expression of an organism's genotype, in other words its the form of the trait that is expressed.
 * 1) 39....Genetics Terms and Mendel...........4/2/09

Answer or do the following items. Answer in complete sentences without using pronouns. Use the list of facts below. 11. What observation of Mendel's didn't agree with the “blending hypothesis?” 12. Why did Mendel cut the male parts off the flowers of his plants? 13. Why did Mendel transfer pollen between flowers with a toothbrush? 14. What was the P generation? The P generation is ...... 15. Describe the types of pea plants used for the P generation. Use some of the terms above in this description. 16. Make a Punnett square for the P generation. A cross of a homozygous dominant plant with a homozygous recessive plant. 17. What was the F1 generation? 18. What observation did Mendel make of the F1 generation's phenotype? Mendel observed .......... 19. What was the genotype of the F1 generation? The genotype was ........... 20. Make a Punnett square for F1 generation. A cross of two hybrid plants. 21. How was the F2 generation produced? 22. How many phenotypes were observed in the F2 generation? Use the word phenotype in your answer. 23. What did Mendel conclude from the reappearance of the reappearance of the recessive trait in the F2 generation? 24. How are traits related to genes? 25. How are genes related to alleles?
 * __Incomplete sentences__ or __the use of pronouns__ will result in __half credit__.**

Mendel's Experiment as a list of facts.
 * The blending hypothesis of heredity is that an offspring's trait is just a blending of the parental traits.
 * Mendel raised pea plants and never observed a blending of contrasting forms of a trait in their offspring.
 * Mendel's experiments involved crossing pure breeding plants with contrasting forms of a traits.
 * To stop self pollination, Mendel snipped the pollen producing structures off the flowers. (Anthers)
 * To control cross pollination between flowers, Mendel transferred pollen with a paintbrush.
 * Mendel called the first plants he crossed the P generation.
 * Mendel started by crossing pure breeding plant with contrasting forms of a trait.
 * The genotypes of the plants used for this cross was homozygous dominant and homozygous recessive.
 * Mendel observed that crossing purebred plants with contrasting traits resulted in offspring with only one trait and no mixing.
 * Mendel observed that crossing purebred plants with contrasting phenotypes resulted in offspring with only one phenotypes
 * Mendel called the offspring from the first cross the F1 generation.
 * The genotype of the F1 generation is heterozygous and Mendel called them hybrids.
 * Mendel called the form of the trait expressed by the F1 generation the dominant trait.
 * Mendel called the form of the trait that was not expressed in the F1 generation the recessive trait.
 * Mendel then let the plants of the F1 generation self pollinate to produce a second group of offspring called the F2 generation.
 * Mendel observed that the crossing of the F1 generation resulted in offspring that expressed both of the original traits.
 * Mendel observed that the trait that disappeared in the F1 generation reappeared in the F2 generation.
 * Mendel found that there were 3 plants with the dominant trait to every 1 plants with the recessive trait in the F2 generation.
 * Mendel crossed plants with seven different contrasting traits and found that the F1 generation express only the dominant trait, but the F2 generation expressed both the dominant and recessive traits in a 3:1 ratio every time. (75% to 25%)
 * Because the recessive trait disappeared in the F1 generation and then reappeared in the F2 generation, Mendel reasoned that traits are controlled by a pair of factors and an offspring receives one from each parent.
 * Today we know that genes are sections of chromosomes that contain instructions for a trait.
 * Today we know that most organism have two copies of every gene and chromosome, one from each parent.
 * Today we know that the factors that control a trait are genes and different forms of genes are called alleles, where one can be dominant and the other recessive.

Answer in __complete__ sentences for full credit. No indefinite pronouns. All pronouns used should refer back to a noun in your sentence and not a noun in the question. 1. In terms of traits, what is a purebred? 2. How are purebred pea plants produced? 3. How did Mendel control the cross pollination (between different plants) in the pea plants he studied? 4. How did Mendel alter the pea plants to stop self pollination ? Mendel crossed two generations of pea plants, so he worked with three generation total. 5. What did he call the generation he started with? 6. What were the genotypes of this starting generation? 7. How many phenotypes were present in the starting generation? 8. What did he call the first group of offspring? 9. What was the genotype of the first group of offspring? 10. How many phenotypes were present in first offspring group? 11. What did he call the second group of offspring? 12. How many phenotypes were present in the second group of offspring? 13. What was the ratio of the phenotypes in the second group of offspring? 14. What was the genotype of offspring that were out numbered in the above ratio? Mendel's Conclusions: 15. How did Mendel know the mixing hypothesis was wrong? 16. What was Mendel's hypothesis on how traits were controlled? 17. What lead Mendel to reason that traits must be controlled by two factors where one is received from each parent? 18. What do we call these factors that control traits today? 19. What do we call different forms of these factors today? 20. Draw a Punnett square for the cross of a heterozygous dog with the dominant trait of black fur and a homozygous dog with blond fur. (Use the second letter of the alphabet in the square.) What is the probability of a puppy's fur bing black? Anothr helpful item to read:
 * 1) 38....Mendel's Experiments...............4/1

MENDEL'S EXPERIMENTS

Analyzing statistics was just one of the requirements of Mendel's work. Another was patience. Mendel worked for more than eight years on his pea plant experiments. Mendel chose the garden pea plant for three reasons: the structure of the pea flowers, the presence of distinctive traits, and the rapid reproduction cycle. These characteristics enabled Mendel to isolate and control variables and to produce observable results that he could duplicate. The structure of the pea flower enabled Mendel to isolate an important variable-fertilization. In fertilization, the male plant gamete, located in pollen produced by the anther, is transferred to the female plant gamete, located at the base of the pistil. The relatively closed structure of the pea flower petals makes it very easy for pollen from the anther to fertilize the pistil of the same flower. This process is called self-fertilization. If a plant or any organism receives the same genetic traits from both of its parents, it is called purebred. Self-fertilization produces purebred pea plants. Mendel also altered plants and transferred pollen by hand. He used a paint brush to transfer the pollen and cut of the pollen producing parts. By controlling pollination and preventing self-fertilization, Mendel crossbred plants, producing hybrids. A hybrid is an organism that receives different forms of a genetic trait from each parent. Garden pea plants have some traits that are easy to see, which made it possible for Mendel to produce observable results. Mendel studied seven traits. Each of these traits is unusual in that it has only two distinct forms. For example, the pea pods are either yellow or green. There is no intermediate, or blended, color. The height of the plant is either tall or short, never medium. Distinct traits like this are rare in nature, as you will see later in this unit. The distinct traits in pea plants allowed Mendel to see his results without guesswork. Another important feature of pea plants is that most plants reproduce in about 90 days. The short reproductive cycle gave Mendel results relatively quickly and allowed him to repeat the experiments many times to test his results.

MENDEL'S OBSERVATIONS Mendel began his experiments using two different groups of purebred plants. He called this generation the parental, or P generation. He called the first generation of offspring the first filial generation, because "filial" refers to offspring. He gave this generation the notation F1. Mendel allowed F, plants to self-fertilize, producing the second filial, or F2 generation. Figure 6.4 shows Mendel's pea plant crosses and results using pea plants with either yellow or green peas. What results did Mendel expect? According to the blending hypothesis, the green and yellow peas of Mendel's plants in the P generation should have blended to produce chartreuse offspring. Instead, Mendel found that all of the F, hybrid plants had yellow peas. There were neither green nor chartreuse peas in the first generation of pea plants, even though one of the parent plants had green peas. When Mendel let the F, hybrid plants self-fertilize, he found green peas in the F2 generation. About 75 percent of the plants in the F2 generation had yellow peas and 25 percent of the plants had green peas. In other words, there was a ratio of three pea plants with yellow peas to one with green peas, or 3:1. Again, there were no chartreuse peas. Mendel repeated his experiments for the other six traits. For each trait, he observed the same results in the F1 generation-all of the F, plants were only one form of the trait. Mendel defined each form of the trait as either dominant or recessive. A dominant form appeared in the F, generation. A recessive form did not appear in the F, generation. For pea color, yellow is the dominant form and green is the recessive. According to Figure 6.5, which other six forms are dominant? In the F2 generation of his experiments, Mendel found that there were always two types of plants. About 75 percent of the F2 plants showed the dominant form of the trait. About 25 percent of the F2 plants showed the recessive form of the trait. How did these results disprove the blending hypothesis?

MENDEL'S CONCLUSIONS Mendel's experiments showed that the blending hypothesis was wrong. He never observed pea plants with mixtures of two forms of a trait, such as chartreuse pea color. Mendel reasoned that forms of a trait must remain separate in offspring. Mendel hypothesized that each trait is controlled by a distinct "factor." Since there were two forms of each trait, Mendel realized that there must be at least two forms of each factor. Mendel was surprised that recessive forms of traits disappeared in the F, generation but reappeared in the F. He reasoned that, for every trait, a pea plant must carry a pair of factors which could affect each other. When a trait is inherited, Mendel concluded, the offspring receives one factor from each parent. We now know that the Mendel's "factors" are genes. Genes are sections of a chromosome that code for a trait. Most organisms have two copies of every gene and chromosome, one from each parent. We refer to the different forms of Mendel's factors as alleles. An allele is a distinct form of a gene. If an organism has two different alleles for a trait, only one is expressed, or visible. A dominant allele is a form of a gene that is fully expressed when two different alleles are present. A recessive allele is a form of a gene that is not expressed when paired with a dominant allele. Mendel published an account of his experiments in 1866. At that time, the scientific community was focused on the work of another scientist, Charles Darwin. Mendel's published work went unrecognized for 35 years. As you will learn in the next chapter, the rediscovery of Mendel's work led to the formulation of the basic principles of inheritance.

Can't be made up fourth Quarter.
 * 1) 37....Two Column Notes with Substitute Teacher

Copy as notes. 1. Genetics is the study of how traits are inherited through the interaction of alleles. 2. Heredity is the passing of traits from parent to offspring. 3. An organism has two genes for each trait. 4. Genes can have more than one expression and each different expression is called an allele. 5. During meiosis when sex cells are made, the two alleles separate into different sex cells. 6. Alleles or the two copies of a genes can be represented by two letters. 7. One expression of the gen or allele is represented by a capital letter and the other by a lower case letter. 8. A genotype is the genetic make up of an organism. 9. TT = homozygous = purebred Tt = heterozygous = hybrid tt = homozygous = purebred 10. Phenotype is the expression the alleles present or how the organism looks.
 * 1) 36......Genetics Introduction.....................3/31/09

Restart numbering 1. Genetics: The study of how traits are inherited through the interaction of alleles.

2. Heredity is the passing of traits from parents to offspring.

3. A trait is a characteristic that can be passed from parent to offspring.

4. Traits are controlled by genes on the chromosomes.

5. Gregor Mendel : Father of genetics He recognized the importance of using math in research His experiments were beautifully designed following the scientific method Gathered statistics on over 20,000 pea plants

6. Using statistics math lead him to the ideas of: Dominant and recessive Law of segregation Law of independent assortment

7. Mendel's work was discovered 35 years later separately by three scientist while doing research. Mendel's Pea Plants: He became the pollinator himself He controlled which plants mixed. He performed cross-pollination with a paintbrush He cut of the flowers pollen producing structures to stop self pollination

8. Mendel studied seven traits of pea plants and these traits were expressed in similar patterns when plants with them were crossed. Height, Pod appearance, Pod color, Seed texture, Seed color, flower color, and position of flower on the stem.

9. Mendel observed that, if pure bred purple flowered plants and pure bred white flowered plants were crossed, all the offspring would have purple flowers. He also observed that, if these offspring were crossed, three out of four of the resulting plants would have purple flowers, but one out of four plants would have white flowers.

10. Mendel wanted to explain how a trait could disappear for one generation and reappear the next.

11. Mendel was able to describe what happen when crossing plants, but others would discover chromosomes and genes with advances in microscopes.

12. Alleles are one form of a gene.

13. Sex cell have one form of a gene, because they only have one of each kind of chromosome.

14. Body cells have two genes for a trait because they have two chromosomes. This mean they can have two identical alleles or two different alleles.

15. One may be dominant over another. If this happens, the dominant gene is the one expressed. If not, the recessive trait is expressed.

16. A Dominant trait will always be expressed and will “mask” a recessive trait

17. A recessive trait can only be expressed if there are no dominant alleles present.

18. Steps for using a Punnett square: Capital letters indicate dominant alleles Lower case indicates recessive alleles One parent's genotype (alleles) goes along the top. The other parent's genotype goes down the side. Fill in the boxes using what is above and beside it.

19. Punnet squares show probabilities and not actual results.

If B is brown eye color and b is blue, how many genotype are there? Phenotypes?

20. Punnett squares are used to predict the traits in offspring and in what ratio.

21. Monohybrid crosses are shown with a Punnett square of one trait.

22. Dihybrid crosses are shown with a Punnett square of two traits.

23. Law of Segregation – during gamete formation pairs of factors for one trait (Alleles) separate.

24. Law of Independent Assortment- alleles for different traits go into different gametes randomly.

Page 131 in your textbook. Draw the Punnett squares and answer the questions.

You must be present and working to earn credit. 23 items total.
 * 1) 35......Focus Items /Participation............3/31/09