Teacher Resources
TEACHER RESOURCES
Answer Key
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology1Body Organization and Structure
TEACHER RESOURCES
Directed Reading A
SECTION: BODY ORGANIZATION
1.homeostasis
2.C
3.C
4.If homeostasis is disrupted, cells may not get the materials they need. So, they may be damaged or die.
5.Your body is like a soccer team because each cell in your body has a job in maintaining homeostasis.
6.tissue
7.D
8.C
9.A
10.B
11.Nervous tissue sends out signals to your brain when the stomach is full.
12.connective tissue
13.epithelial tissue
14.organ systems
15.D
16.F
17.K
18.A
19.C
20.J
21.E
22.I
23.B
24.G
25.H
26.The cardiovascular and respiratory systems work very closely together to deliver the materials cells need to survive.
SECTION: THE SKELETAL SYSTEM
1.bone, cartilage, connective tissue
2.B
3.D
4.protection, storage, movement, and blood cell formation
5.ribs, vertebrae, skull
6.minerals or fat
7.marrow
8.osteoblasts
9.spongy bone
10.compact bone
11.compact bone
12.spongy bone
13.Red marrow produces both red and white blood cells. Yellow marrow, found in the central cavity of long bones, stores fat. In children, red marrow fills the center of long bones. Red marrow is replaced with yellow marrow as children become adults.
14.C
15.F
16.E
17.G
18.D
19.B
20.A
21.Bones may be fractured. Bones in joints may be dislocated. A sprain may happen if a ligament is stretched too far or torn.
22.osteoporosis
23.arthritis
SECTION: THE MUSCULAR SYSTEM
1.It is impossible to sit still and never move any muscles at all because somewhere in your body, muscles are always working.
2.B
3.C
4.A
5.voluntary
6.involuntary
7.When you want to move, signals travel from your brain to your skeletal muscle cells. The muscle cells then contract, or get shorter.
8.skeletal muscles, bones
9.flexor
10.extensor
11.biceps
12.triceps
13.Strong muscles can help organs. Contracting muscles squeeze blood vessels and increase blood flow with-out requiring the heart to work more. More endurance also lets muscles work longer without getting tired.
14.resistance exercises
15.weight
16.Answers may vary. Sample answer: Jogging, cycling, skating, swimming, and walking are examples of aerobic exercise.
17.aerobic exercises
18.A
19.B
20.D
21.Anabolic steroids can damage the heart, liver, and kidneys. They can cause high blood pressure. They can cause bones to stop growing if they are taken before the skeleton is mature.
SECTION: THE INTEGUMENTARY SYSTEM
1.C
2.skin, hair, nails
3.water, foreign particles
4.nerve endings
5.sweat glands
6.waster
7.melanin
8.Melanin absorbs ultraviolet light from the sun.
9.D
10.E
11.C
12.D
13.A
14.B
15.F
16.epidermis
17.dermis
18.epithelial
19.keratin
20.collagen
21.D
22.A
23.melanin
24.Hair helps protect skin from ultraviolet light. Hair keeps particles out of your eyes and nose. Hair helps regulate body temperature in most mammals.
25.nail root
26.Damage to the genetic material in the skin cells can cause cancer. Acne can develop if excess oil combines with dead skin cells and bacteria to clog hair follicles.
27.A blood clot forms over a cut to stop
bleeding and keep bacteria from entering the wound. Bacteria-fighting cells then come to the area to kill bacteria. Damaged cells are replaced through cell division. Eventually, all that is left on the surface is a scar.
Directed Reading B
SECTION: BODY ORGANIZATION
1.A
2.C
3.B
4.D
5.C
6.A
7.B
8.organ
9.muscle tissue
10.nervous tissue
11.epithelial tissue
12.organ system
13.B
14.A
15.D
16.B
17.C
18.C
19.A
20.B
21.D
22.B
23.D
24.A
25.C
SECTION: THE SKELETAL SYSTEM
1.cartilage
2.movement
3.ribs
4.minerals
5.marrow
6.B
7.D
8.A
9.B
10.blood vessels
11.compact bone
12.spongy bone
13.C
14.B
15.C
16.A
17.C
18.D
19.A
20.B
21.dislocated joint
22.sprain
23.osteoporosis
24.arthritis
25.fracture
SECTION: THE MUSCULAR SYSTEM
1.A
2.C
3.B
4.A
5.B
6.D
7.C
8.flexor
9.extensor
10.exercise
11.endurance
12.resistance exercises
13.aerobic exercise
14.A
15.B
16.D
17.B
18.C
SECTION: THE INTEGUMENTARY SYSTEM
1.skin
2.integumentary system
3.water
4.nerve endings
5.melanin
6.ultraviolet light
7.sweat glands
8.wastes
9.D
10.C
11.A
12.C
13.A
14.C
15.A
16.B
17.B
18.C
19.A
20.D
21.A
22.D
23.C
24.B
25.cancer
26.acne
27.blood clot
28.bacteria-fighting cells
Vocabulary and Section Summary
SECTION: BODY ORGANIZATION
1.homeostasis the maintenance of a constant internal state in a changing environment
2.tissue: a group of similar cells that perform a common function
3.organ: a collection of tissues that carry out a specialized function of the body
SECTION: THE SKELETAL SYSTEM
1.skeletal system: organ system whose primary function is to support and protect the body and to allow the body to move
2.joint: a place where two or morebones meet
SECTION: THE MUSCULAR SYSTEM
1.muscular system: the organ system whose primary function is movement and flexibility
SECTION: THE INTEGUMENTARY SYSTEM
1.integumentary system: the organ system that forms a protective covering on the outside of the body
2.epidermis: the surface layer of cells on a plant or animal
3.dermis: the layer of skin below the epidermis
Section Review
SECTION: BODY ORGANIZATION
1.Sample answer: Homeostasis is main-tained by cells, tissues, and organs.
2.C
3.integumentary system, muscular system, skeletal system, cardiovascular system, respiratory system, urinary system, reproductive system, nervous system, digestive system, lymphatic system, and endocrine system
4.about 11% (22 bones 206 bones 100 10.7%)
5.Sample answer: The nervous system sends messages to Ta n y a ’s muscular system to bite into the hamburger. Ta n y a ’s jaws, which are part of the skeletal system, help grind up the food. The food moves into Ta n y a ’s stomach, which is part of her digestive system. The digestive system breaks down the food, and the cardiovascular system p i c k s up nutrients from the digestive system to take throughout the body
6.Sample answer: The body would beunable to maintain homeostasisbecause the cells of the body wouldhave too many jobs to do. The cellslikely would not be able to do all ofthese jobs
SECTION: THE SKELETAL SYSTEM
1.Sample answer: The skeletal systemincludes bones, cartilage, andconnective tissue, and it providessupport to the body
2.C
3.Sample answer: Bones protect your organs. Bones store materials that help nerves and muscles function properly. Along with skeletal muscles, bones make it possible to move. Finally, marrow in bones produces blood cells.
4.gliding joints, hinge joints, and ball-and-socket joints
5.Sample answer: Osteoporosis is a disease that causes bones to become less dense. Bones become weak and break more easily. Arthritis is a painful joint disease that causes joints to swell or stiffen.
6.14 days (6 weeks 7 days/week 42 days; 42 days 1/3 14 days)
7.Sample answer: Children are still growing, so they need more blood cells as their bodies get bigger. After children become adults, they don’t need as many new blood cells, so long bones store fat instead.
8.Sample answer: Growth plates are places where bones continue to grow. If children did not have growth plates, their bones would not continue to grow.
SECTION: THE MUSCULAR SYSTEM
1.Sample answer: The muscular system is the group of muscles that allows people to move.
2.A
3.Sample answer: Smooth muscleis found in the digestive tract and inthe walls of blood vessels. Cardiacmuscle is found only in the heart.Skeletal muscle is attached to bonesfor movement
4.Sample answer: Curl-ups are aresistance exercise. Jogging is anaerobic exercise.
5.Sample answer: A strain is an injury in which a muscle or tendon is overstretched or torn. Tendinitis is a condition in which a tendon becomes inflamed when the body doesn’t have enough time to repair the tendon between exercise sessions.
6.87.5 s (35 curl-ups 2.5 curl-ups/s=.87.5 s)
7.Sample answer: An extensor in the back of my arm straightens out my arm as I reach for the book. Flexors in my hand let me close my fingers on the book, and a flexor in my arm bends my arm as I pick up the book.
8.Sample answer: As the heart gets stronger, the heart will likely pump more blood with each beat. The heart will not need to work as hard to pump the same amount of blood. So, heart rate will likely decrease.
SECTION: THE INTEGUMENTARY SYSTEM
1.Sample answer: The integumentary sys-tem is the organ system that forms a protective covering over the body. The epidermis is the outer layer of skin. The dermis lies beneath the epidermis.
2.C
3.Sample answer: The epidermis is the outermost layer of skin. It is made of epithelial tissue. Most of the cells of the epidermis are dead cells that contain keratin. The dermis lies beneath the epidermis and contains sweat glands, hair follicles, nerve fibers, muscle fibers, and blood vessels. The dermis also contains collagen.
4.Sample answer: A hair grows as new cells are added in the hair follicle, which is where the only living cells are located. Nails grow from living cells in the nail root at the base of the nail.
5.Sample answer: A blood clot forms over a cut to stop bleeding and to k e e p bacteria out of the cut. Bacteria-fighting cells come to the area to kill bacteria. Damaged skin cells are replaced through cell division. E v e n t u a l l y, all that is left is a scar.
6.9 mm (0.3 mm/day 30 days 9mm); 109.5 mm (0.3 mm/day 365days 109.5 mm)
7.Sample answer: Except in the hair follicle and in the nail root, hair and nails are made of dead cells, so cutting either does not hurt. Pulling on them, h o w e v e r, affects the living areas of hair and nails in the dermis, where nerve endings are located.
8.Sample answer: The epidermis forms a protective covering of dead cells. The hands and the feet are areas that are often used, so the epidermis in these areas needs to be thicker for better protection.
Chapter Review
1.joint
2.Homeostasis
3.epidermis
4.integumentary system
5.organ
6.skeletal system
7.C
8.C
9.A
10.D
11.Sample answer: Muscles are connected to bones by tendons. When a muscle that connects two bones contracts, the bones are pulled closer together. Muscles often work in pairs.
12.Sample answer: The skeletal system includes the bones, cartilage, and connective tissue, whose primary function is to support the body. The skeletal system protects organs, stores minerals, allows movement, and produces blood cells.
13.Sample answer: Your muscular system works with your skeletal system to help you move.
14.fractures, dislocations, sprains, osteoporosis, and arthritis
15.Sample answer: Aerobic exercise is steady, moderately intense activity that improves endurance. Resistance exercise strengthens skeletal muscles. During resistance exercise, muscles work against resistance, or weight.
16.Sample answer: Damage to genetic material in skin cells can cause skin c a n c e r. If oil glands in skin produce t o o much oil, hair follicles may be clogged, which causes acne.
17.An answer to this exercise can be found at the end of the Teachers Edition.
18.Sample answer: Leg bones are long and skinny while skull bones are thin and wide. Many skull bones are curved. Leg bones enable walking and standing while skull bones are designed to protect the brain.
19.Sample answer: The skin on the elbows is thin, loose, and sometimes rough. The skin on the fingertips is thicker, but more sensitive to touch. The skin on elbows allows the elbow to bend because it is loose and can stretch. The skin on the fingers is important for the sense of touch.
20.The robot would need a ball-and-socket joint. A ball-and-socket joint allows movement in all directions.
21.Sample answer: Dense bones that are filled with marrow weigh more than hollow bones. Because most birds fly, they need lighter bones. So, birds’ bones are hollow.
22.Sample answer: If a bone is broken, flexors or extensors likely will not work properly. These muscles will not be able to pull on a bone in the way that they do when a bone is not broken. Also, if the area where the muscle attaches is damaged, the ability of the muscle to pull on the bone may be affected.
23.dermis; collagen
24.Sample answer: Sweat glands release sweat to cool the body.
25.Sample answer: Oil glands release oil to keep hair flexible and to waterproof the epidermis.
26.C
27.F; hair follicle
Reinforcement
THE HIPBONE’S CONNECTED TO THE…
From left to right and top to bottom: pelvic girdle, fibula, skull, clavicle, ribs, humerus, vertebral column, radius, ulna, femur, patella, and tibia
1.hinge joint
2.ball-and-socket joint
3.gliding joint
MUSCLE MAP
Skeletal Muscle: moves bones, involuntary, voluntary, often work in pairs
Cardiac Muscle: in the heart, involuntary, pumps blood
Smooth Muscle: in blood vessels, in the digestive tract, moves food, involuntary
Leg on left-hand side: flexor
Leg on right-hand side: extensor
Critical Thinking
1.Answers may vary. Sample answers: Engineered tissues would provide a permanent solution for skin and organ loss. Patients would not have to wait for a matching donor organ.
2.Answers may vary. Sample answers: The procedure is relatively new, so it is probably very expensive. The long-term success rate is unknown.
3.Answers may vary. Sample answer: No. The use of engineered tissue is unethical. Scientists should not have the power to make living skin or body organs. Sample answer: Yes. The use of engineered tissue is ethical because it improves the quality of life for burn patients.
4.Answers may v a r y. Sample answer: W h a t have been the long-term results o f other patients who underwent the same treatment? What does this procedure cost? What are the other possible treatments?
5.Answers may vary. Sample answer: Internal organs are more complex than skin. While skin is made up of one type of tissue, internal organs are made up of a combination of tissues. Each type of tissue has specialized cells that perform specific functions.
Section Quiz
SECTION: BODY ORGANIZATION
1.B6.F
2.D7.E
3.A8.A
4.D9.D
5.C10.B
SECTION: THE SKELETAL SYSTEM
1.G6.E
2.I7.B
3.A8.D
4.F9.H
5.J10.C
SECTION: THE MUSCULAR SYSTEM
1.B6.D
2.D7.D
3.A8.A
4.A9.C
5.C10.B
SECTION: THE INTEGUMENTARY SYSTEM
1.B6.E
2.F7.D
3.D8.B
4.A9.B
5.C10.C
Chapter Test A
1.G13.C
2.J14.A
3.B15.A
4.E16.B
5.A17.C
6.H18.A
7.D19.D
8.C20.B
9.F21.A
10.I22.B
11.D23.C
12.B
Chapter Test B
1.melanin
2.cardiac
3.epithelial
4.ligaments
5.skeletal
6.D
7.C
8.B
9.A
10.protection, storage, movement, and blood cell production
11.Voluntary muscle action is under your control. Involuntary muscle action is not under your control.
12.Osteoporosis causes the bones to become less dense. Bones become weak and break more easily.
13.A strain is an injury in which a muscle or tendon is overstretched or torn. Tendinitis happens when someone exercises too often, and a tendon becomes inflamed as a result.
14.Homeostasis maintains a stable internal environment within the body.
15.Answers may vary. Sample answer: While the patient was wearing the cast, the muscles around the bone were not being exercised, and the muscle became smaller and weaker. Physical therapy allows a patient to gradually restore the lost strength with less risk of injury. It helps increase both strength and endurance.
16.If the organs of the lymphatic system were not working properly, the body would be less able to eliminate bacteria and viruses. This problem could cause a person to be more prone to get various diseases or illnesses.
17.If a person’s body did not produce melanin, he or she would probably have very light skin and white hair.
18.spongy bone; Spongy bone provides most of the strength and support for a bone.
19.cartilage; Cartilage covers and cushions the place where two bones meet. Growth plates of cartilage in children provide a place for bones to grow.
20.a. tissues; b. organ systems; c. skeletal system; d. integumentary system; e. joints; f. tendons.
Chapter Test C
1.B
2.B
3.C
4.C
5.D
6.D
7.C
8.D
9.A
10.B
11.D
12.C
13.B
14.A
15.organ
16.marrow
17.osteoporosis
18.flexor
19.compact bone
20.spongy bone
21.blood vessels
Standardized Test Preparation
READING
Passage 1
1C
2.F
3.B
Passage 2
1.D
2.G
3.D
INTERPRETING GRAPHICS
1.C
2.G
3.B
4.H
MATH
1.A
2.F
3.C
4.I
5.B
Vocabulary Activity
Across
3.compact bone
8.joint
10.sweat glands
11.spongy bone
17.integumentary organs
21.ligaments
22.hair follicles
23.muscle tissue
24.tissue
25.melanin
26.nervous
Down
1.organ
2.cartilage
3.connective tissue
4.epidermis
5.extensor
6.homeostasis
7.tendons
9.smooth muscle
12.epithelial tissue
13.flexor
14.cardiac
15.dermis
16.muscular system
18.skeletal muscles
19.skeletal system
20.marrow
SciLinks Activity
Answers may vary. Students should include major organs, function in the body, and a picture for three different body systems. Sample answer: Digestive system; stomach, small intestine, large intestine; function is to break down food so that the body can use its nutrients.
Performance-Based Assessment
PROCEDURE
2.Answers may vary. Sample answer: We used the paper-towel rolls, string, and toothpicks.
3.Answers may vary. Sample answer: My model resembles a knee joint. It resembles a knee joint because I can open and fold my model just as a knee joint allows you to bend and straighten the leg.
DRAW CONCLUSIONS
4.Sample answer: Hinge joints are stronger than other types of joints. Hinge joints move in only one direction, so you can use them to make more focused movements.
5.Sample answer: Hinge joints move in only one direction, while ball-and-socket joints have a broad range of motion. Hinge joints also are not as flexible as other types of joints, such as gliding joints.
Seeing Is Believing
1.Answers may vary. Many students may note that rates of growth vary.
2.Answers may vary. Some students will answer that their nails did not grow at a constant rate.
DRAW CONCLUSIONS
3.The nails of the dominant hand grow faster than those of the other hand. Damage to the nail root can affect how quickly a nail grows. Also, circulation to the area affects growth. If one hand receives poor circulation, the nail will grow at a slower rate.
Seeing Is Believing
4.Some students may note differences in nail growth. While these differences likely are not related to height, they are related to nutrition. Someone who does not have enough of certain minerals, such as calcium and magnesium, in his or her diet will have slower nail growth. Nail growth is also affected by age, time of year, and gender. Nail growth slows as people get older. Nails grow faster in the summer than they do in the winter. Often, men’s nails grow faster than women’s nails do.