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Pearson Science Grade 8D – Human Biology & Health
Answers for Workbook Questions
The Pearson materials incorporate a Guided Reading and Study Workbook that is
designed to be an enhancement to the textbook as the student progresses. The answers to
the workbook questions are provided in this answer key, laid out by page number and
type. Please keep in mind that a separate answer key is available for the end-of-unit and
end-of-chapter assessments in the textbook.
Page
Number
Question
Category
Answers
Page 9 Body
Organization and
Homeostasis
Use Target
Reading Skills
I. Cells
A. Structures of cells
B. Functions of cells
II. Tissues
III. Organs and organ systems
IV. Homeostasis
A. Homeostasis in action
B. Maintaining homeostasis
C. Stress and homeostasis
Pages 10-12 Body
Organization and
Homeostasis
Introduction 1. a. cells
b. tissues
c. organs
d. organ systems
Cells 2. cell
3. d
4. nucleus
5. The cytoplasm is the area between the cell membrane and the nucleus. It contains
a clear, jellylike substance in which other cell structures are found.
6. true
Tissues 7. A tissue is a group of similar cells that perform the same function.
8. Muscle: Makes parts of the body move by contracting, or shortening; muscles
Nervous: Carries messages back and forth between the brain and other parts of the
body; brain, spinal cord, or nerves
Connective: Supports the body and connects all its parts; blood, fat, cartilage, bones,
or tendons
Epithelial: Covers the surfaces of the body, inside and out; skin, lining of digestive
system
Organs and
Organ Systems 9. organ
10. c
11. true
12. An organ system is a group of organs working together to perform a major
function.
13. d
14. f
15. c
16. a
17. e
18. b
Homeostasis 19. homeostasis
20. When a person perspires, the liquid evaporates and the skin cools down. The
removal of heat helps the body maintain a constant body temperature.
Page 13 The Skeletal
System
Use Target
Reading Skills
Sample answers:
What does the skeleton do? (The skeleton provides shape and support, helps you to
move, protects organs, produces blood cells, and stores minerals and other
materials.)
How do joints allow movement? (Joints allow bones to move forward or
backward, in a circle, in a rotating motion, and in a gliding motion.)
How strong are bones? (Bones can absorb more force without breaking than can
granite or concrete.)
What can I do to care for my bones? (Eat a well-balanced diet and get plenty of
exercise.)
Pages 13-16 The Skeletal
System
What the Skeletal
System Does 1. a. Provides shape and support
b. Enables the body to move
c. Protects the internal organs
d. Produces blood cells
e. Stores certain materials until the body needs them
2. c
3. vertebrae
4. Muscles pull on the bones to make the body move.
5. d
6. blood cells
Joints of the
Skeleton 7. A joint is a place in the body where two bones come together.
8. immovable joints, movable joints
9. c
10. Allows forward or backward motion; knees and elbows
Allows the bone to swing in a circle; shoulder blades and hips
Allows one bone to rotate around another; neck
Allows one bone to slide over another; wrists and ankles
11. ligaments
Bones-Strong and
Living 12. a, d
13. Bone cells form new tissue during growth, in response to the force of the body’s
weight, and to heal broken bones.
14. a. compact bone
b. bone marrow
c. spongy bone
d. outer membrane
15. d
16. a
17. b
18. c
19. cartilage
20. b, d
Taking Care of
Your Bones 21. A combination of a balanced diet and regular exercise will keep the bones
healthy.
22. osteoporosis
Page 17 Diagnosing Bone
and Joint Injuries
Use Target
Reading Skills
Sample answers:
Effect on body cells:
X-rays—Can cause damage
MRI—Causes no damage
Types of injuries identified:
X-rays—Bone (fracture and dislocation)
MRI—Bone and soft tissue
How they work:
X-rays—pass through soft tissue and are absorbed by bone; bone shows on film
MRI—Magnetic energy causes atoms to vibrate, which forms a pattern that can be
converted into an image
Cost:
X-rays—low cost
MRI—high cost
Pages 18-19 Diagnosing Bone
and Joint Injuries
Common Skeletal
System Injuries 1. c
2. a
3. b
4. false
Identifying
Injuries 5. X-rays are a form of energy that travels in waves.
6. true
7. a. X-rays cannot be used to view injuries to soft tissues.
b. The energy in X-rays can damage body cells.
8. magnetic resonance imaging
9. A person is exposed to short bursts of magnetic energy inside the MRI scanner.
The magnetic energy causes the body’s atoms to vibrate. A computer analyzes the
vibration patterns and produces an image of the area.
10. a, b
Treating Injuries 11. arthroscope
12. false
Pages 20-21 The Muscular
System
Use Target
Reading Skills
Sample answers:
How does skeletal muscle help my body move?
(Skeletal muscles are attached to the ends of bones and provide the force to move
them.)
Where is smooth muscle found? (On the inside of many internal organs)
What are the characteristics of cardiac muscle?
(It is found only in the heart; it is like smooth muscle because it is involuntary and
like skeletal muscle because it is striated.)
Types of Muscle 1. a. Involuntary muscles are not under conscious control.
b. Voluntary muscles are under conscious control.
2. b
3. Attached to bones of skeleton, voluntary, striated
Smooth, involuntary, not
Only in heart, involuntary, striated
4. tendon
5. true
6. heartbeats
Muscles at Work 7. Muscles contract when they receive messages from the nervous system.
8. false
9. Because muscle cells can only contract, not extend, skeletal muscles must work
in pairs. While one muscle contracts, the other muscle returns to its original length.
10. contracts, original length
Pages 22-23 The Skin
Use Target
Reading Skills
Main Idea:
The skin has several important functions.
Sample details:
The skin forms a barrier against disease-causing microorganisms and harmful
substances, and prevents the loss of important fluids; the skin helps the body
maintain a steady temperature; the skin helps to eliminate wastes through
perspiration; the skin contains nerves that gather information about the environment;
skin cells produce vitamin D that helps your body absorb calcium.
The Body’s
Tough Covering 1. b, d
2. true
3. They warn you that something in the surroundings may have injured you.
4. vitamin D
The Epidermis 5. epidermis
6. false
7. two weeks
8. true
9. true
The Dermis 10. dermis
11. a, c, d
12. pores
13. Follicles are structures in which strands of hair grow within the dermis.
Caring for Your
Skin 14. a healthful diet, limiting sun exposure, keeping skin clean
Page 24
Key Terms 1. skeletal
2. pore
3. joint
4. tendon
5. fracture
6. marrow
7. imaging
8. cartilage
9. sprain
Diagonal word is epidermis.
Pages 25-28 Food and Energy
Use Target
Reading Skills
I. Why You Need Food
A. Nutrients
B. Energy
C. Nutritionists’ Recommendations
II. Carbohydrates
A. Simple Carbohydrates
B. Complex Carbohydrates
C. Nutritionists’ Recommendations
III. Fats
A. Kinds of Fats
B. Cholesterol
C. Nutritionists’ Recommendations
IV. Proteins
A. Amino Acids
B. Complete and Incomplete Proteins
V. Vitamins and Minerals
A. Fat-Soluble and Water-Soluble Vitamins
B. Importance of Vitamins
C. Importance of Minerals
VI. Water
Why You Need
Food 1. a. The materials for growing and for repairing tissues; b. The energy for
everything you do
2. true
3. nutrients
4. a. carbohydrates b. fats c. proteins d. vitamins e. minerals f. water
5. calories
6. true
Carbohydrates 7. energy
8. false
9. b
10. a
11. b
12. a
Fats 13. Fats are high-energy nutrients that are made up of carbon, oxygen, and
hydrogen.
14. b
15. a. Form part of the structure of cells b. Protect and support internal organs
c. Insulate the body to keep in heat
16. Unsaturated Fats: Liquid; Most oils, such as olive and canola oils
Saturated Fats: Solid; Meat and dairy products
Proteins 17. proteins
18. a. Needed for tissue growth and repair b. Play a part in chemical reactions in
cells c. Can serve as a source of energy
19. d
20. false
21. b
22. a
23. a
24. b
Vitamins &
Minerals 25. Vitamins are helper molecules in a variety of chemical reactions within the
body.
26. b, c, d
27. minerals
28. Your body gets minerals by eating plant foods or animals that have eaten plants.
29. c
30. d
31. a
32. b
Water 33. water
34. The body’s vital processes—including chemical reactions such as the
breakdown of
nutrients—take place in water.
Pages 29-30 Healthy Eating
Use Target
Reading Skills
Sample questions and answers:
Q: What is the Food Guide Pyramid?
A: The Food Guide Pyramid classifies food into groups to help people plan a healthy
diet.
Q: What kind of information can I find on a food label?
A: serving size, Calories, Percent Daily Value, and ingredients
Guidelines for a
Healthy Diet 1. The Food Guide Pyramid classifies foods into six groups. It also tells how many
foods to eat from each group every day.
2. The foods in the bottom level of the pyramid—foods from grains, such as bread,
cereals, rice, and pasta—should make up the largest part of the diet.
3. sparingly
Food Labels 4. true
5. serving size
6. A single serving of this food supplies the body with 110 Calories of energy.
7. The Percent Daily Value shows how the nutritional content of one serving fits
into the diet of a person who needs 2,000 Calories each day.
8. false
9. weight
10. It can alert you to substances that have been added to the food that could make
you sick.
Pages 31-33 The Digestive
Process Begins
Use Target
Reading Skills
Sample Answer:
What You Know
1. Food is digested in the stomach.
2. The digestive system breaks down food.
3. Teeth break foods into small pieces.
What You Learned
1. Teeth carry out mechanical digestion.
2. An enzyme in saliva breaks down starches into sugars.
3. Muscle contractions called peristalsis push food toward the stomach.
Function of the
Digestive System 1. food; blood; wastes
2. Digestion is the process by which the body breaks down food into small nutrient
molecules.
3. false
4. absorption
5. These materials are removed from the body as wastes.
The Mouth 6. saliva
7. b
8. An enzyme in saliva breaks down starch into sugar molecules.
The Esophagus 9. b
10. c
11. a
12. d
The Stomach 13. a, c, d
14. a. Mucus coats and protects the stomach lining. b. Cells in the stomach lining
are quickly replaced.
Pages 34-35 Final Digestion
and Absorption
Use Target
Reading Skills
Main Idea: Chemical digestion takes place in the small intestine.
Details: Food mixes with enzymes and secretions; starches, proteins, and fats are
digested chemically. Enzymes and secretions are produced by the small intestine,
liver, and pancreas.
The Small
Intestine 1. Almost all chemical digestion and absorption of nutrients takes place in the small
intestine.
2. a. small intestine; b. liver; c. pancreas
3. liver
4. bile
5. The gallbladder stores the bile produced by the liver and delivers it to the small
intestine.
6. starches, proteins, fats
7. villi
8. true
The Large
Intestine 9. true
10. Absorb water into the bloodstream; Prepare undigested food for elimination
11. rectum
12. b
Page 36
Key Terms 1. pancreas
2. mucus
3. vitamin
4. absorption
5. Food Guide Pyramid
6. gallbladder
7. enzyme
8. saturated fat
9. Key Term: nutrient
Definition: A nutrient is a substance in food that provides the raw materials and
energy the body needs to carry out all its essential processes.
Pages 37-39 The Body’s
Transport
System
Use Target
Reading Skills
Bottom oval: Left side of heart; Left oval: Body
The
Cardiovascular
System
1. circulatory
2. blood vessels; blood
3. Needed substances, waste products, disease fighting cells
The Heart 4. Each time the heart beats, it pushes blood through the blood vessels of the
cardiovascular system.
5. Upper: atria; two; to receive blood that comes into the heart. Lower: ventricles;
two, to pump blood out of the heart
6. valve
7. pacemaker; oxygen
8. It makes the heart contract at a normal rate.
Two Loops 9. arteries, capillaries, veins
10. Blood is pumped from the right atrium to the right ventricle and then to the
lungs. In the lungs, blood picks up oxygen and releases carbon dioxide. Blood then
flows to the left atrium.
11. From the right atrium, the next arrow points up the artery to the lungs and then
down the vein from the lungs. From the lungs, the arrow points to the left atrium
and then down to the artery to the body and finally, from the vein from the body to
the right atrium. (see photo on p 77 of your text)
12. aorta
Pages 40-41 A Closer Look at
Blood Vessels
Use Target
Reading Skills
Sample answers:
Artery: Carries blood away from heart; Thick walls consisting of three cell layers
with thick muscle in the middle layer
Capillary: Exchange of materials between the blood and body cells; Thin walls
consisting of one cell layer
Vein: Carries blood back to the heart; Thick walls consisting of three cell layers
with thin muscle in the middle layer
Arteries 1. heart
2. false
3. b, c
4. true
Capillaries 5. In the capillaries, materials are exchanged between the blood and the body’s
cells.
6. diffusion
Veins 7. Veins carry blood back to the heart.
8. a. Contraction of nearby skeletal muscles;
b. Valves that prevent blood from flowing backward;
c. Breathing movements that squeeze veins in the chest
Blood Pressure 9. Blood pressure is the pressure that blood exerts against the walls of blood vessels.
10. c
Page 42 Blood and
Lymph
Use Target
Reading Skills
Sample details: Plasma is the liquid part of blood; red blood cells take up oxygen
and deliver it to cells in the body; white blood cells fight disease; platelets help form
blood clots.
Pages 43-44 Blood and
Lymph
Blood 1. plasma
2. White blood cells; Platelets
3. water
4. a. nutrients; b. chemical messengers; c. wastes
5. Red blood cells pick up oxygen in the lungs and carry it to cells in the body.
6. Hemoglobin is an iron-containing protein that binds chemically to oxygen
molecules. It is found in red blood cells.
7. They fight disease.
8. a. There are fewer of them. b. They are bigger.
c. They have nuclei. d. Most live for months or even years.
9. true
10. Fibrin weaves a net of tiny fibers across a cut, which traps blood cells and
platelets that form a clot.
11. A blood transfusion is the transfer of blood from one person to another.
12. Type A blood has clumping proteins that act against the marker molecules on
type B blood cells.
13. The Rh factor is a marker on red blood cells that determines whether a person’s
blood type is Rh positive or Rh negative.
Blood Types 14. b
15. d
16. a
17. c
The Lymphatic
System 18. The lymphatic system is a network of vein like vessels that returns fluid to the
bloodstream.
19. lymph
20. Lymph nodes filter the lymph, trapping bacteria and other microorganisms that
cause disease.
Pages 45-47 Cardiovascular
Health
Use Target
Reading Skills
Possible questions and answers include:
Q. What are some cardiovascular diseases?
A. atherosclerosis, hypertension
Q. How can a person keep healthy?
A. Exercise regularly, eat a healthy diet, and avoid smoking Cardiovascular
Diseases 1. Atherosclerosis is a condition in which an artery wall thickens as a result of the
buildup of fatty materials.
2. Cholesterol is a waxy, fatlike substance that can restrict the flow of blood in
arteries.
3. blood; oxygen; heart attack
4. Hypertension is a disorder in which a person’s blood pressure is consistently
higher than normal.
5. Hypertension makes the heart work harder and also may damage the walls of the
blood vessels.
6. Treatment includes regular exercise, careful food choices, limited sodium intake,
and medication.
Keeping Healthy 7. a. saturated fat; b. trans fats; c. cholesterol
8. false
9. Exercise strengthens heart muscles. High-fat foods can lead to atherosclerosis;
weight gain can strain the cardiovascular system. Smoking increases the risk of heart
attack.
Page 48
Key Terms Down: 1. capillaries, 2. plasma, 3. coronary, 8. vein
Across: 4. pacemaker, 5. pulse, 6. atrium, 7. valve, 9. lymph
Pages 49-53 The Respiratory
System
Use Target
Reading Skills
Possible answers:
Path of Air
Air enters the nose
To the pharynx
To the trachea
To the bronchi
To the lungs
Respiratory
System Functions 1. a, d
2. a. Move oxygen from the outside environment into the body; b. Remove carbon
dioxide and water from the body
3. Oxygen
4. Respiration is the process in which oxygen and glucose undergo a series of
chemical reactions inside cells to release energy.
5. a. energy; b. carbon dioxide; c. water
6. false
7. a, c, d
The Path of Air 8. true
9. nostrils; pharynx; trachea; bronchi
10. A sneeze shoots particles and bacteria out of the nose and into the air.
11. throat
12. b
13. d
14. a
15. c
16. b, c
17. cartilage
18. false
19. choke
20. c
21. true
22. The blood picks up oxygen from the air inside the alveoli.
Gas Exchange 23. Oxygen passes through the walls of the alveoli and through the capillary walls
into the blood. Carbon dioxide and water pass from the blood into the alveoli.
24. The alveoli provide a large surface area in a relatively small space.
How You
Breathe 25. false
26. The diaphragm is a large, dome-shaped muscle that plays an important role in
breathing.
27. larger; decreases; inhale; smaller; lungs
28. larynx
29. Vocal cords are folds of connective tissue stretching across the opening of the
larynx that produce the voice.
30. Muscles make the vocal cords contract. Air from the lungs rushes through the
opening between them. The movement of the vocal cords makes the air vibrate to
create a sound.
Page 54 Smoking and
Your Health
Use Target
Reading Skills
Possible effects: Damage to protective cilia and risk of cancer due to tar; increase in
blood pressure and addiction due to nicotine; risk over time of chronic bronchitis,
emphysema, lung cancer, and atherosclerosis.
Pages 55-56 Smoking and
Your Health
Chemicals in
Tobacco Smoke 1. Tar: Dark, sticky substance that forms when tobacco burns; Clumps cilia together
so they can’t keep harmful materials out of the lungs Carbon monoxide: Colorless,
odorless gas produced when things are burned; Binds to hemoglobin in red blood
cells in place of oxygen
Nicotine: Speeds up the nervous system and heart
Health Problems
and Smoking 2. b, c
3. a. chronic bronchitis;
b. emphysema;
c. lung cancer;
d. atherosclerosis
4. false
5. emphysema
6. Emphysema is caused when chemicals in tobacco smoke damage lung tissue and
breathing passages.
7. true
8. Chemicals from tobacco smoke enter the blood and are absorbed by blood
vessels. The chemicals irritate the blood vessels, which causes a buildup of the fatty
material that causes atherosclerosis.
9. true
10. In passive smoking, people involuntarily inhale the smoke from other people’s
cigarettes, cigars, or pipes.
Pages 57-59 The Excretory
System
Use Target
Reading Skills
Possible student questions and answers are these:
Where are nephrons located? (In the kidneys)
What three main materials are filtered out of
the blood? (Urea, water, glucose)
What happens to these filtered materials? (Most of the water and glucose are
reabsorbed. Most of the
urea remains as urine.)
Introduction 1. The excretory system collects wastes produced by cells and removes the wastes
from the body.
2. excretion
The Excretory
System 3. urea and excess water
4. c
5. a
6. b
7. blood; ureters; urinary bladder; urethra
Filtration of
Wastes 8. Nephrons are tiny structures that remove wastes from blood and produce urine.
9. a. Wastes and needed materials are removed from the blood. b. Much of the
needed material is returned to the blood and wastes are eliminated from the body.
10. false
11. glucose and water; urea and other wastes
12. Analyzing the contents of urine can detect some medical problems, such as
diabetes or kidney malfunction.
Excretion and
Homeostasis 13. water
14. false
15. a. lungs b. skin; c. liver
16. The liver breaks down proteins into urea, and converts part of hemoglobin
molecules into substances such as bile.
Page 60
Key Terms 1. urea
2. alveoli
3. bronchitis
4. nephron
5. diaphragm
6. urethra
7. larynx
8. tar
9. cilia
10. nicotine
11. kidney
Answer: respiration
Pages 61-63 Infectious
Disease
Use Target
Reading Skills
Sample answer:
What You Know
1. Bacteria and viruses can cause disease.
2. You can catch a cold from another person.
3. Dogs can spread rabies.
What You Learned
1. Organisms that can cause disease are called pathogens.
2. Some bacteria produce poisons, or toxins.
3. Some pathogens can spread through soil, food, or water.
Understanding
Infectious
Disease
1. pathogens
2. An infectious disease is a disease that can pass from one organism to another.
3. true
Kinds of
Pathogens 4. b, c
5. false
6. Bacteria, Viruses, Fungi, Protists
7. a. By directly damaging body cells, b. By producing a poison, or toxin, that
damages cells
8. Viruses cause disease by damaging or destroying cells as they reproduce inside
them.
9. d
How Pathogens
Are Spread 10. a. infected people b. soil, food, water c. a contaminated object d. an infected
animal
11. b, d
Page 64 The Body’s
Defenses
Use Target
Reading Skills
Accept all logical definitions for Key Terms.
Pages 65-67 The Body’s
Defenses
Barriers That
Keep Pathogens
Out
1. The first line of defense is barriers, such as the surfaces of the skin, breathing
passages, mouth, and stomach, that keep pathogens from getting into the body.
2. Harmful chemicals are in oil and sweat; pathogens fall off with dead skin cells;
tightly packed layer of dead skin cells forms a barrier. Mucus and cilia trap
pathogens. Coughing and sneezing force pathogens out of body. Saliva and stomach
acid destroy pathogens.
The
Inflammatory
Response
3. inflammatory response
4. Fluid and certain types of white blood cells leak from blood vessels into nearby
tissues. The white blood cells then fight the pathogens.
5. phagocytes
6. Blood vessels in the area widen to increase the flow of blood to the area.
7. A fever helps the body fight infection because some pathogens may not grow and reproduce well at higher temperatures.
The Immune
System 8. immune response
9. a. T cells; b. B cells
10. T cell; T cells; B cells; Antibodies
11. Lymphocytes can distinguish between different kinds of pathogens and react to
each pathogen with a defense targeted specifically to it.
12. Antigens are molecules on cells that the immune system recognizes either as
part of the body or as coming from outside the body.
13. a. Clump pathogens together; b. Keep pathogens from attaching to body cells; c. Make it easier for phagocytes to destroy the pathogens
AIDS 14. AIDS is caused by a virus, HIV, that attacks the immune system.
15. T cells
16. true
17. a, d
Pages 68-70 Preventing
Infectious
Disease
Use Target
Reading Skills
Sample answers: Active Immunity—The body makes antibodies. Memory cells
recognize antigens.
Immunity may last for years or a lifetime.
Passive Immunity—Antibodies are given; the body does not make antibodies.
Immunity lasts only a few months. Immunity can be acquired from the mother
during pregnancy. Both types can prevent diseases. Both may involve an injection.
Introduction 1. immunity
2. a. active immunity; b. passive immunity
Active Immunity 3. Active immunity occurs when a person’s own immune system produces
antibodies in response to the presence of a pathogen.
4. true
5. Memory cells recognize a pathogen’s antigen and start the immune response
quickly.
6. vaccination
7. Vaccines usually consist of pathogens that have been weakened or killed but can
trigger the immune system to go into action.
8. antibiotic
9. true
10. a. Get plenty of rest. b. Eat well-balanced meals. c. Drink plenty of fluids.
Passive Immunity 11. passive
12. false
13. Antibodies from the mother’s body pass into the baby’s body.
Pages 71-73 Noninfectious
Disease
Use Target
Reading Skills
Possible questions and answers:
What is an allergy? (An allergy is a disorder in which the immune system is overly
sensitive to a foreign
substance.)
How does diabetes affect the body? (A person’s body cells do not have enough
glucose.)
What causes cancer? (Different factors cause cancer, such as heredity and
carcinogens.)
Introduction 1. false
2. noninfectious
Allergies 3. An allergy is a disorder in which the immune system is overly sensitive to a
substance that is not normally found in the body.
4. allergen
5. a, b, c, d
6. histamine
7. true
8. Asthma is a disorder in which the respiratory passages narrow, causing a person
to wheeze and become short of breath.
Diabetes 9. c
10. diabetes
11. false
12. b, c
13. Type I: Childhood or early adulthood; The pancreas produces little or no
insulin. Injections
of insulin
Type II: Adulthood; Either the pancreas doesn’t make enough insulin or body cells
do not respond normally to insulin. Possibly get insulin injections; control symptoms
through diet, weight control, and exercise.
Cancer 14. Cancer is a disease in which cells multiply over and over, destroying healthy
tissue in the process.
15. tumors
16. a. Inherited characteristics; b. Factors in the environment called carcinogens
17. true
18. a, d
Pages 74-75 Cancer and the
Environment
Use Target
Reading Skills
Possible answers include the following:
Cause Effect
UV Light Skin Cancer
Vinyl chloride Cancers of the liver,
brain, or lungs
Arsenic Cancers of the liver,
bladder, kidneys, and
lungs
Linking Cancer
to the
Environment
1. He observed that many chimney sweeps developed skin cancer.
2. false
3. To reduce the risk of cancer, the carcinogens need to be removed or people need
to be protected from them.
4. The EPA identifies environmental carcinogens and develops strategies to protect
people from them.
Environmental
Carcinogens
Today
5. Vinyl Chloride: A colorless gas used to make PVC, which is used in plastic
products; Liver, brain, or lung cancer; When people inhale the vapors over long
periods of time
Ultraviolet Light: A part of sunlight; Skin cancer; By overexposure to sunlight
Page 76 Key Terms A = 5 D = 9 G = 10
B = 13 E = 8 H = 3
C = 6 F = 7 I = 11
All blocks add up to 24
Pages 77-79 How the
Nervous System
Works
Use Target
Reading Skills
Sample questions and answers:
What is a sensory neuron? (A neuron that picks up stimuli from the internal or external environment and
converts each stimulus into a nerve impulse)
What does an interneuron do?
( It carries nerve impulses from one neuron to another.)
Functions of the 1. a. Receives information; b. Responds to information; c. Maintains homeostasis
Nervous System 2. false
3. a. the environment; b. inside the body
4. b
5. false
6. The nervous system directs the body to respond appropriately to the information it receives.
The Neuron 7. c
8. b
9. d
10. a
11. true
12. nerve
13. a. sensory neurons; b. interneurons; c. brain; d. motor neurons
How a Nerve
Impulse Travels 14. synapse
15. The axon tips release chemicals that enable the impulse to cross the gap at the
synapse.
Page 80 Divisions of the
Nervous System
Use Target
Reading Skills
Accept all logical definitions for Key Terms.
Pages 81-83 Divisions of the
Nervous System
Central Nervous
System 1. true
2. brain
3. spinal cord
The Brain and
Spinal Cord 4. true
5. a. The skull; b. Layers of connective tissue; c. Fluid between layers of
connective tissue
6. b
7. c
8. a
9. b
10. a
11. false
12. right
13. brain; peripheral nervous system
14. a. Vertebral column b. Layers of connective tissue c. A watery fluid
Peripheral
Nervous System 15. It consists of a network of nerves that branch out from the central nervous
system and connect it to the rest of the body.
16. controls voluntary actions; controls involuntary actions
Reflexes 17. A reflex is an automatic response that occurs very rapidly and without
conscious control.
18. a, b
Nervous System
Injuries 19. concussion
20. Wear a helmet during some activities to help protect your head.
21. All the nerve axons in that region are damaged, so impulses cannot pass through
them, causing loss of movement in some part of the body.
Pages 84-86 The Senses
Use Target
Reading Skills
The Senses I. Vision
A. How light enters your eye
B. How light is focused
C. How you see an image
D. Correcting nearsightedness
E. Correcting farsightedness
II. Hearing and balance
A. How sound is produced
B. The outer ear
C. The middle ear
D. The inner ear
E. The inner ear and balance
III. Smell and taste
IV. Touch
Introduction 1. nerve impulses
Vision 2. b
3. e
4. d
5. c
6. a
7. false
8. a. The image is turned right-side up. b. The images from each eye are combined
to form a single image.
9.
Vision Problems
Questions Nearsightedness Farsightedness
What is wrong? Cannot see objects that are far
away.
Nearby objects look
blurry.
What causes it? The eyeball is too long. The eyeball is too short.
How is it corrected? Wear eyeglasses with a
concave lens.
Wear eyeglasses with a
convex lens.
Hearing and
Balance 10. sound
11. Sounds are made by a material that is vibrating, or moving back and forth.
12. false
13. funnel
14. d
15. The cochlea is a snail-shaped tube that is lined with receptors that respond to
sound.
16. semicircular canals
17. true
Smell and Taste 18. false
Touch 19. skin
20. Pain alerts the body to possible danger.
Pages 87-90 Alcohol and
Other Drugs
Use Target
Reading Skills
Possible effects: Slowing of central nervous system; sleepiness; slow reaction time
Introduction 1. drug
Drug Abuse 2. drug abuse
3. b, d
4. tolerance
5. c
6. true
7. Drug users may pay a fine or go to jail. Drug abusers have a hard time doing well
in school or keeping a job.
8. true
Kinds of Abused
Drugs 9. c
10. e
11. a
12. d
13. b
Alcohol 14. b
15. true
16. digestive
17. true
18. The abuse of alcohol can cause the destruction of cells in the brain and liver,
and it can also lead to addiction and emotional dependence.
19. alcoholism
20. true
Page 91 Key Terms withdrawal
brain stem
dendrite
retina
iris
depressant
response
cerebrum
pupil
drug
axon
synapse
Hidden Question: What is a neuron?
Answer: A neuron is a nerve cell.
Pages 92-94 The Endocrine
System
Use Target
Reading Skills
Sample effects: Activate other glands; Regulate growth from infancy to adulthood;
Regulate blood pressure; Regulate water balance.
Hormones and
the Endocrine
System
1. The endocrine system controls many of the body’s daily activities as well as
long-term changes such as growth and development.
2. endocrine glands
3. false
4. hormone
5. Hormones turn on, turn off, speed up, or slow down the activities of different
organs and tissues.
6. b, c
7. target cells
Functions of
Endocrine Glands 8. d
9. b
10. e
11. a
12. c
13. c, d
14. It is a small endocrine gland that communicates with the hypothalamus to
control many body activities.
15. true
Negative
Feedback 16. When the amount of a particular hormone in the blood reaches a certain level,
the endocrine system sends signals that stop the release of that hormone.
17. a. pituitary; b. thyroid; c. cells; d. TSH; e. thyroxine
Pages 95-98 The Male and
Female
Reproductive
Systems
Use Target
Reading Skills
The Menstrual Cycle
Days 1–4 Menstrual discharge
Days 5–13 Developing egg
Days 14–15 Ovulation
Days 16–22 Egg moves through fallopian tube
Days 23–28 Egg enters uterus
Sexual
Reproduction 1. e
2. a
3. c
4. f
5. b
6. d
7. a. sperm; b. egg
8. false
Male
Reproductive
System
9. sperm, the hormone testosterone
10. b
11. Testosterone controls the development of physical characteristics in men.
12. scrotum
13. true
14. An environment in which sperm can swim; Nutrients that give moving sperm a
source of energy
15. penis
Female
Reproductive
System
16. The female reproductive system produces eggs, and if an egg is fertilized,
nourishes a developing baby until birth.
17. egg cells; hormones such as estrogen
18. Estrogen triggers the development of some adult female characteristics and
helps egg cells develop.
19. Ovary, fallopian tube, uterus, vagina
The Menstrual
Cycle 20. c
21. menstrual cycle
22. An egg develops in an ovary, and the uterus prepares for the arrival of a
fertilized egg.
23. pregnancy
24. b, d
Pages 99-102 The Human Life
Cycle
Use Target
Reading Skills
Explain that knowing the definitions of Key
Terms helps students understand what they read.
Development
Before Birth 1. fetus
2. true
3. embryo
4. Embryo is called a fetus; internal organs have developed; has dark eye patches,
fingers, and toes. Tissues develop into more recognizable shapes; bones are distinct;
heartbeat can be heard; fetus begins to kick. Brain surface develops grooves and
ridges; lungs develop; eyelids can open and eyelashes and eyebrows grow.
Protection and
Nourishment 5. amniotic sac
6. The placenta is a membrane that becomes the link between the developing
embryo and the mother.
7. The umbilical cord contains blood vessels that link the embryo to the mother, but
the two circulatory systems remain separated by a thin barrier.
8. true
Birth 9. labor, delivery, afterbirth
10. a, c
11. The baby’s endocrine system releases adrenaline, which increases the baby’s
heart rate. The baby cries or coughs to clear its lungs and fill them with air.
12. a
13. b
14. b
15. a
16. false
Growth and
Development 17. true
18. d
19. false
20. b, d
21. Adolescence is the stage of development when children become adults
physically and mentally.
22. Puberty is the period of sexual development in which the body becomes able to
reproduce.
23. b, c, d
24. b, c, d
Page 103 Key Terms hormone
embryo
fetus
puberty
zygote
semen
ovary
estrogen
