Bio Ch 20, 21, 22

2. The force of blood pushing against the walls of blood vessels is called ________.

blood pressure

2. Which of the following statements about the amino acids that are required by adult humans is true? a. The human body produces 20 amino acids. b. There are eight amino acids used as building blocks for human proteins. c. Amino acids are the building blocks of carbohydrates. d. Amino acids are the building blocks of proteins.

d. Amino acids are the building blocks of proteins.

25. Which of the following would NOT be found in the lower small intestine? a. microvilli c. a large surface area b. villi d. a smooth surface

d. a smooth surface

48. The figure shown indicates a(n) a. cell body. c. target cell. b. dendrite. d. axon.

d. axon

45. Which of the following sequences correctly describes the pathway that a signal travels in a neuron? a. cell body to axon to dendrite c. dendrite to axon to cell body b. axon to dendrite to cell body d. dendrite to cell body to axon

d. dendrite to cell body to axon

31. After certain knee injuries, patients experience a swelling because of an accumulation of fluid within the knee. This condition is referred to as "water on the knee." Which of the following is a likely source of this fluid? a. the tendons around the knee c. spongy bone b. the ligaments around the knee d. the synovial sac

d. the synovial sac

1. When the ________ of the heart contracts, blood is pumped into the systemic circuit.

left ventricle

42. As a muscle contracts, which of the following things happens? a. The Z disks move closer together. c. The muscle creates energy. b. The sarcomeres extend. d. The myofibrils break down.

a. The Z disks move closer together.

5. A genetic mutation has altered a signaling molecule found embedded within cell membranes. This signaling molecule is most likely a a. protein. c. fat. b. carbohydrate. d. dietary fiber.

a. protein

35. Which of the following statements about the peripheral nervous system (PNS) is NOT true? a. The PNS may stimulate muscles. b. The PNS may integrate and process information. c. The PNS may inhibit endocrine cells. d. The PNS may stimulate organs.

b. The PNS may integrate and process information.

46. The structures that carry signals away from the cell body of a neuron are called a. dendrites. c. nuclei. b. axons. d. synapses.

b. axons.

38. Where in the body would you expect to find voluntary muscle that has a banded appearance? a. within the wall of the esophagus c. in the heart b. in a muscle that bends the knee d. within the wall of the stomach

b. in a muscle that bends the knee

6. A newborn is diagnosed shortly after birth with a rare heart defect that prevented the valve between the left atrium and the left ventricle from fully forming. Which of the following would be an expected outcome of this defect? a. Oxygen poor and oxygenrich blood would mix. b. Blood would flow through the body in more than one direction. c. Body cells would receive less oxygen rich blood than normal. d. Blood flow from the left ventricle to the body would increase.

c. Body cells would receive less oxygen rich blood than normal.

20. The liver secretes bile to the a. pancreas. c. gallbladder. b. small intestine. d. large intestine.

c. gallbladder

1. Blood leaving the right ventricle of the heart travels next to the a. right atrium. c. lungs. b. body. d. left ventricle.

c. lungs.

19. Which letter in this figure identifies the site where most digestion and nutrient absorption takes place? a. A c. C b. B d. D

d. D

37. Vanessa has been lifting weights to increase strength in her arms. Which of the following statements about the muscles she is strengthening is true? a. They lack myofibrils. b. They lack a banded appearance. c. They are involuntary muscles. d. They have tendons that are connected to bones.

d. They have tendons that are connected to bones

3. The majority of carbon dioxide is carried in the blood component called ________.

plasma

7. Valuable solutes, such as sugar and small proteins, that enter a nephron are ________ by capillaries.

reabsorbed

32. Which of the following functions occurs in the urinary bladder but NOT in nephrons? a. urine storage c. secretion b. filtration d. reabsorption

a. urine storage

5. ________ is the process of expelling carbon dioxide from the lungs and taking oxygen into the lungs.

Breathing breathing

35. Which of the following statements about cardiac muscle is true? a. Cardiac muscle is like skeletal muscle, because skeletal muscle has involuntary contractions. b. Cardiac muscle is like smooth muscle, because smooth muscle has a banded appearance. c. Cardiac muscle contains bands like skeletal muscle, but its contractions are involuntary like smooth muscle. d. Cardiac muscle is like smooth muscle, because it contains no bands.

c. Cardiac muscle contains bands like skeletal muscle, but its contractions are involuntary like smooth muscle.

16. The function of the esophagus is to a. break down food physically. b. break down food chemically. c. carry food to the stomach. d. prepare undigested material and waste for disposal.

c. carry food to the stomach.

1. Carbohydrates and fats are both a. digested and absorbed in the human stomach. b. sources of amino acids. c. used as energy sources. d. indigestible unless they are consumed together.

c. used as energy sources.

7. The liquid portion of human blood cannot absorb enough oxygen to meet the body's demands. However, ________ in our red blood cells greatly increase(s) the oxygen carrying capacity of human blood. a. carbon dioxide c. water b. ions d. hemoglobin

d. hemoglobin

34. Which of the following statements about the muscle shown in this figure is true? a. It is under our conscious control. c. It lacks nuclei. b. It lacks myofibrils. d. It is an involuntary muscle.

a. It is under our conscious control.

21. Which of the following things happens during inhalation? a. Oxygen rich air enters the alveoli. b. Lung volume decreases. c. Pressure in the lungs remains constant. d. The diaphragm relaxes.

a. Oxygen rich air enters the alveoli.

30. If an athlete damages a ligament in his or her knee, he or she has damaged a. a connection between two bones. b. a connection between bone and muscle. c. a mineral based component of his or her skeleton. d. a nonliving component of his or her skeleton.

a. a connection between two bones.

13. Which of the following features could be found in a vein, but NOT in an artery? a. a one way valve c. Oxygen rich blood b. muscle d. blood that is under high pressure

a. a one way valve

24. In cystic fibrosis, parts of the respiratory tract can become clogged with mucus, inhibiting gas exchange. The area(s) of the respiratory tract where gases are directly exchanged is/are the a. alveoli. c. diaphragm. b. bronchi. d. trachea.

a. alveoli

27. The structure that is highlighted in this illustration of a knee joint is a a. bone. c. tendon. b. ligament. d. synovial sac.

a. bone.

42. When eating dessert, you notice the sweetness of sugar when ________ are stimulated. a. chemoreceptors c. thermoreceptors b. photoreceptors d. mechanoreceptors

a. chemoreceptors

19. For a human to inhale, the rib muscles and the diaphragm must a. contract, decreasing pressure inside the lungs. b. relax, increasing pressure inside the lungs. c. contract, increasing pressure inside the lungs. d. relax, decreasing pressure inside the lungs.

a. contract, decreasing pressure inside the lungs.

44. The branched structures on a nerve cell that receive information are called a. dendrites. c. neurons. b. axons. d. synapses.

a. dendrites

9. People with sickle cell disease have deformed hemoglobin molecules and often suffer muscle pains, even at low levels of exertion. These symptoms might occur because the deformed hemoglobin a. is unable to carry the amount of oxygen required for normal muscle activities. b. cannot diffuse across the cells' membranes from the blood plasma. c. causes damage to the muscle cells as it enters the muscle. d. decreases the ratio of surface area to volume in a person's lungs.

a. is unable to carry the amount of oxygen required for normal muscle activities.

20. Which of the following sequences correctly describes the journey of a molecule of oxygen from the pharynx to an alveolus? a. pharynx to trachea to bronchus to bronchiole to alveolus b. pharynx to bronchiole to bronchus to trachea to alveolus c. pharynx to trachea to bronchiole to bronchus to alveolus d. pharynx to bronchus to bronchiole to trachea to alveolus

a. pharynx to trachea to bronchus to bronchiole to alveolus

15. The advantage of chewing food is that this process a. provides mechanical digestion and increases the surface area of the food for further digestion. b. makes food immediately ready for nutrient absorption in the stomach. c. increases the amount of vitamins in the food. d. decreases the surface area of the food to speed digestion.

a. provides mechanical digestion and increases the surface area of the food for further digestion

36. You accidentally rest your hand on a hot stove. This sensory information will ultimately be relayed to the appropriate part of your brain by the a. thalamus. c. cerebrum. b. hypothalamus. d. cerebellum.

a. thalamus.

12. Which component of whole blood would an investigator examine to determine the concentration of dissolved carbon dioxide or hormones, such as testosterone? a. the plasma c. the white blood cells b. the platelets d. the red blood cells

a. the plasma

8. Which of the following organs plays a role in producing vitamin D? a. the skin c. the stomach b. the small intestine d. the large intestine

a. the skin

23. How rapidly an organism can absorb nutrients generally depends on a. the surface area available for absorption. b. how quickly the nutrient can diffuse into the stomach. c. the passive mechanisms that carry the nutrient into the organism. d. the volume of the organism that is taking up the nutrients.

a. the surface area available for absorption

41. Sensory neurons that contain specialized membrane channels activated by moderate temperatures are a. thermoreceptors. c. pain receptors. b. chemoreceptors. d. electroreceptors.

a. thermoreceptors.

14. Large blood vessels that return deoxygenated blood from the legs to the heart are a. veins. c. arteries. b. capillaries. d. arteries and capillaries.

a. veins.

4. Blood vessels that are designed to carry blood under high pressure are called ________. Blood vessels that have thin, porous walls are called ________.

arteries, capillaries

29. Which of the following things would you expect to happen if a knee joint was formed without any cartilage? a. The knee would lack any ability to bend. b. Bones within the knee would experience friction. c. The joint would be able to bend past its normal position. d. The knee would lack synovial fluid.

b. Bones within the knee would experience friction.

30. If you were to compare the filtrate that is leaving the glomerulus to urine that is exiting the body, you would find that some substances — such as hydrogen ions and toxins — are more concentrated in the urine. Which of the following statements explains this process? a. Hydrogen ions and toxins are reabsorbed by capillaries. b. Hydrogen ions and toxins are secreted from capillaries. c. Hydrogen ions and toxins are not filtered in nephrons. d. Hydrogen ions and toxins are stored in nephrons.

b. Hydrogen ions and toxins are secreted from capillaries.

22. Which of the following statements best explains why starch molecules must be broken down before they can be absorbed by the small intestine? a. They are toxic to the cells of the small intestine. b. They are too large to pass through the plasma membrane of the intestinal cells. c. They must be broken down in order to extract the essential amino acids they contain. d. The cells of the small intestine are much too small to contain them.

b. They are too large to pass through the plasma membrane of the intestinal cells.

9. Babies may receive an injection of vitamin K at birth. Which of the following is the most likely reason why an injection of vitamin K would be given? a. Vitamin K is required for calcium absorption, and babies need to build strong bones. b. Vitamin K is required to prevent bleeding, and babies are born with low levels of this vitamin. c. Vitamin K is required for the formation of visual pigments in the eyes, and babies use their eyes more often than their other senses. d. Vitamin K is required to build cell membranes, and babies are growing rapidly.

b. Vitamin K is required to prevent bleeding, and babies are born with low levels of this vitamin.

29. Which of the following statements accurately describes the movement of water and waste within a nephron? a. Water and waste both filter through the glomerulus additional water is later secreted from capillaries. b. Water and waste both filter through the glomerulus water is later reabsorbed from capillaries. c. Only waste filters through the glomerulus water is secreted by capillaries along the length of the nephron. d. Only water filters through the glomerulus waste is secreted by capillaries along the length of the nephron.

b. Water and waste both filter through the glomerulus water is later reabsorbed from capillaries.

5. Shortages of iron in our diet can cause iron deficiency anemia, a condition that reduces the amount of hemoglobin in red blood cells. Iron deficiency anemia is a potentially serious condition that is characterized primarily by a. a change in the color of blood from its normal red to various shades of blue and purple. b. a reduction in the blood's capacity to transport oxygen. c. a delay in the time required for the blood to clot and a potential for extensive blood loss in the event of trauma. d. a reduction in the concentration of white blood cells and an increased vulnerability to infection.

b. a reduction in the blood's capacity to transport oxygen.

18. The human liver produces bile, a substance that a. aids in the absorption of vitamin C. b. allows fats to dissolve more easily in the watery contents of the gut. c. neutralizes the acids that are produced by pepsin. d. breaks the bonds between amino acids.

b. allows fats to dissolve more easily in the watery contents of the gut.

7. As an experiment, a person who wishes to avoid getting ill during the winter significantly boosts his or her vitamin intake by taking multiple vitamin supplements. This action could a. help the person live decades longer. b. be dangerous, because the human body needs vitamins only in small amounts. c. help the person look decades younger. d. reduce the person's fiber intake.

b. be dangerous, because the human body needs vitamins only in small amounts.

15. The blood vessels that allow diffusion between blood and nearby body cells are a. veins. c. arteries. b. capillaries. d. veins and capillaries.

b. capillaries.

26. As nutrients move across an intestinal villus, most of the nutrients are absorbed by a. lymphatic vessels. c. epithelial cells. b. capillaries. d. collagen.

b. capillaries.

40. The sensory receptor types that provide information about body position and balance to help you coordinate your dance moves are a. chemoreceptors. c. magnetoreceptors. b. mechanoreceptors. d. electroreceptors.

b. mechanoreceptors

14. Which of the following sequences correctly describes the journey of a potato chip through our digestive tract? a. mouth to esophagus to stomach to liver to small intestine to large intestine to anus b. mouth to esophagus to stomach to small intestine to large intestine to anus c. mouth to stomach to esophagus to pancreas to small intestine to large intestine to anus d. mouth to esophagus to stomach to large intestine to small intestine to anus

b. mouth to esophagus to stomach to small intestine to large intestine to anus

26. The concentration of oxygen in blood plasma near an alveolus is lowered when a. nearby red blood cells release carbon dioxide. b. oxygen diffuses into red blood cells and binds to hemoglobin. c. carbon dioxide diffuses into the alveolus. d. oxygen diffuses into the alveolus.

b. oxygen diffuses into red blood cells and binds to hemoglobin.

12. Minerals are a. organic compounds. b. required by the human body in small amounts. c. not harmful to humans when ingested in large amounts. d. created by chemical reactions within cells.

b. required by the human body in small amounts.

44. Which of the following sequences correctly describes the organization of muscle tissue from smallest to largest component? a. myofibrils to sarcomeres to muscle fibers b. sarcomeres to myofibrils to muscle fibers c. muscle fibers to sarcomeres to myofibrils d. sarcomeres to muscle fibers to myofibrils

b. sarcomeres to myofibrils to muscle fibers

2. Another name for the "pacemaker" of the heart is the a. atrioventricular (AV) node. c. atrium. b. sinoatrial (SA) node. d. ventricle.

b. sinoatrial

39. The power that moves food along your esophagus comes from a. skeletal muscle. c. cardiac muscle. b. smooth muscle. d. voluntary muscle.

b. smooth muscle

6. The most likely potential problem faced by a person who is following a low protein diet is the failure to a. take in the carbon, hydrogen, and oxygen required for life. b. take in enough essential amino acids c. take in enough calories to survive. d. produce vitamins and minerals required by living organisms.

b. take in enough essential amino acids

41. Bending your elbow involves a. smooth muscle contraction. b. the use of voluntary muscles. c. the use of involuntary muscles. d. the lengthening of sarcomeres beyond their resting length.

b. the use of voluntary muscles.

11. A college student tracks his diet for several weeks as part of a nutrition project. During the tracking period, he realizes that his diet is rich in yellow and orange fruits and vegetables, citrus fruits, nuts, and fish, but that he tends to avoid most leafy green vegetables. Which of the following vitamins is most likely deficient in his diet? a. vitamin B12 c. vitamin A b. vitamin K d. vitamin C

b. vitamin K

3. Which of the following nutrients have the lowest energy content per gram? a. fats c. proteins b. vitamins d. carbohydrates

b. vitamins

8. Which of the following statements about hemoglobin is true? a. Hemoglobin is an enzyme involved in the process of cellular respiration. b. Hemoglobin transports oxygen from cells that are undergoing cellular respiration to red blood cells. c. Hemoglobin binds to oxygen and releases it near cells that are performing cellular respiration. d. Hemoglobin makes the blood more acidic, enabling it to absorb more oxygen.

c. Hemoglobin binds to oxygen and releases it near cells that are performing cellular respiration.

17. Blood flows rapidly within the arterial system but slows dramatically as it enters the capillaries. What is the benefit of having blood move slowly through the capillaries? a. It enables the capillaries to conserve the blood's pressure gradient so that enough pressure remains to return the blood to the heart. b. It provides the time needed for white blood cells to capture any bloodborne pathogens that might be present. c. It ensures that the blood has enough time to exchange material with the surrounding cells. d. It decreases the probability of frictional scarring on the capillary wall and the subsequent development of atherosclerosis.

c. It ensures that the blood has enough time to exchange material with the surrounding cells.

33. One of the most common knee injuries is the tearing of the anterior cruciate ligament (ACL). How would an injury like this affect the function of the knee? a. Ligaments attach muscle to bone, so tearing of the ligament would mean that the knee muscles would no longer be able to cause the joint to bend. b. Ligaments lubricate the cartilage in a joint, and tearing the ligament would let the lubricant leak out. This would cause bones in the knee to grind against each other, making it painful to bend the knee. c. Ligaments hold the bones of the knee in the proper orientation. Tearing the ligament could disrupt the alignment of the knee, making the knee difficult to bend. d. Ligaments are the muscles that surround a joint. Muscle tears can be painful, but they heal quickly and they usually do not affect knee function.

c. Ligaments hold the bones of the knee in the proper orientation. Tearing the ligament could disrupt the alignment of the knee, making the knee difficult to bend.

38. If you were to step on a nail with your right foot, which of the following things would NOT happen? a. Sensory input from your right foot would be processed in your central nervous system. b. Motor output would travel to both of your legs your right foot would be raised and your left leg would stiffen to prevent you from falling over. c. Motor output from your right leg would be interpreted by your brain as sensory input. d. The thalamus would filter and sort the sensory input that is entering your brain.

c. Motor output from your right leg would be interpreted by your brain as sensory input.

3. One side of the heart pumps blood into the pulmonary circuit, and the other side of the heart pumps blood to the systemic circuit. How do these different functions affect the structure of the heart? a. The left side of the heart has one large chamber, whereas the right side has two chambers. b. The right side of the heart has three chambers, whereas the left side has two chambers. c. The left side of the heart has a thicker muscular wall than the right side. d. The right side of the heart has a thicker muscular wall than the left side.

c. The left side of the heart has a thicker muscular wall than the right side.

23. Air that is entering the lungs has a. a higher concentration of carbon dioxide than air in an alveolus. b. a higher concentration of both carbon dioxide and oxygen than air in an alveolus. c. a higher concentration of oxygen and a lower concentration of carbon dioxide than air in an alveolus. d. a lower concentration of oxygen but the same concentration of carbon dioxide as air in an alveolus.

c. a higher concentration of oxygen and a lower concentration of carbon dioxide than air in an alveolus.

24. The lower region of the small intestine is structured to create large amounts of surface area so that it can more efficiently a. produce enzymes to break food down into smaller molecules. b. grind food down into smaller molecules. c. absorb the chemical building blocks that are produced by digestion. d. eliminate waste products.

c. absorb the chemical building blocks that are produced by digestion.

31. If the glomerulus remained intact but other capillaries were not in close physical contact with nephrons, which of the following functions would NOT be lost? a. secretion of toxins c. filtration of plasma b. reabsorption of water and sugars d. concentration of urine

c. filtration of plasma

37. As you are driving to school one morning, the driver in front of you suddenly slams on his brakes and turns right without using his turning signal. Despite the potentially irritating situation, you remain calm because your ________ helped you control your emotions. a. cerebrum c. limbic system b. thalamus d. reticular formation

c. limbic system

39. Which of the following sensory receptor types is NOT found in humans? a. chemoreceptors c. magnetoreceptors b. mechanoreceptors d. thermoreceptors

c. magnetoreceptors

36. If a drug attacked and destroyed involuntary muscle cells only, which of the following body functions would be affected? a. movement of the arms b. movement of the legs c. movement of materials through the digestive system d. movement of the eyes

c. movement of materials through the digestive system

43. Muscle contraction is caused by a. movement of bones that anchor the muscles. b. sarcomeres moving along other sarcomeres. c. myosin filaments sliding along actin filaments. d. contraction of actin and myosin filaments.

c. myosin filaments sliding along actin filaments.

43. The external signals and information that are received by an organism are called a. sensory receptors. c. stimuli. b. dendrites. d. nodes.

c. stimuli.

28. The structure that is highlighted in this illustration of a knee joint is a a. bone. c. tendon. b. ligament. d. synovial sac.

c. tendon.

28. When blood arrives at an alveolus, a. the concentration of oxygen is lower in the alveolus than in the blood. b. the concentration of carbon dioxide is higher in the alveolus than in the blood. c. the concentration of carbon dioxide is higher in the blood than in the alveolus. d. the concentration of carbon dioxide in the blood is equal to the concentration of oxygen in the alveolus.

c. the concentration of carbon dioxide is higher in the blood than in the alveolus

17. Food passing through our digestive tract would contain the fewest nutrients when it reaches which of the following organs? a. the small intestine c. the large intestine b. the stomach d. the esophagus

c. the large intestine

4. Which of the following does NOT facilitate exchange of materials by diffusion? a. cells lying within 0.03 millimeters of blood vessels b. a large surface area within alveoli c. the presence of the extracellular matrix within connective tissue d. thin, porous walls in capillaries

c. the presence of the extracellular matrix within connective tissue

11. Why do humans rely on a circulatory system to distribute oxygen? a. Diffusion does not occur in organisms that have more than about 300 cells. b. Humans do not need as much oxygen as small organisms do, so we use inefficient transport systems like the circulatory system rather than diffusion. c. Humans need an internal transport system in order to quickly replace oxygen that is lost because of our high surface area of skin. d. Diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process.

d. Diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process.

40. Which of the following statements about what happens during a muscle contraction is true? a. Actin and myosin filaments both shorten in length. b. Actin filaments shorten in length when myosin filaments bind to actin. c. Myosin filaments become attached to the Z disks in a sarcomere. d. Myosin filaments slide along actin filaments.

d. Myosin filaments slide along actin filaments.

45. Which of the following statements about myofibrils is true? a. They consist of a single sarcomere. c. They have no Z bands. b. They contain a single muscle fiber. d. They contain many sarcomeres.

d. They contain many sarcomeres.

13. Pancreatic cancer is an especially dangerous disease in humans because the pancreas is a. the organ that produces and stores bile. b. the site of synthesis for all the essential amino acids. c. one of the organs through which food must pass on its way to the large intestine. d. an organ that manufactures many different kinds of digestive enzymes.

d. an organ that manufactures many different kinds of digestive enzymes.

32. The knee is part of the ________ skeleton, which is designed primarily for ________. a. axial, protection c. appendicular, protection b. Axial, motion d. appendicular, motion

d. appendicular motion

16. The pulmonary ________ carries ________ blood from the heart to the lungs. a. vein oxygen rich c. Vein oxygen poor b. artery oxygen rich d. artery oxygen poor

d. artery oxygen poor

47. The ________ of a neuron contain(s) all of the structures, such as a nucleus, that are common to animal cells. a. dendrites. c. synapses. b. axons. d. cell body.

d. cell body.

33. Which of the following processes is NOT a function of nephrons? a. filtration of plasma c. secretion of some toxins b. reabsorption of water d. diffusion of oxygen into body cells

d. diffusion of oxygen into body cells

4. If you were a bird about to embark on a long migratory journey, which of the following nutrients would you want to have stored in large quantities? a. sugars c. vitamins b. proteins d. fats

d. fats

21. One of the advantages of the villi that line the small intestine is that they a. decrease the surface area available for food absorption. b. increase the speed at which vitamins are broken down. c. increase the amount of mechanical breakdown that occurs. d. increase the surface area available for food absorption.

d. increase the surface area available for food absorption.

10. At high altitudes, gases are less concentrated. You might gasp for air, because a. the surface area of your lungs will be decreased. b. the amount of hemoglobin in your blood will decrease. c. hemoglobin will not be able to bind to oxygen as well at a higher altitude. d. the amount of oxygen that could diffuse into your blood will be decreased.

d. the amount of oxygen that could diffuse into your blood will be decreased.

22. Which of the following structures has the smallest diameter? a. the pharynx c. the bronchi b. the trachea d. the bronchioles

d. the bronchioles

34. As you take this exam, which part of your brain is helping you decide which answer is correct? a. the cerebellum c. the thalamus b. the pons d. the cerebral cortex

d. the cerebral cortex

25. The breaking open of alveoli in people who have emphysema decreases their rate of gas exchange because a. there is a decrease in the distance between the air they breathe in and their blood. b. there is less pressure in the lungs to force the oxygen to dissolve in their blood. c. the concentration of oxygen in their lungs becomes much greater than the concentration of oxygen in their blood. d. their lungs have less surface area available for diffusion.

d. their lungs have less surface area available for diffusion.

18. The structure that is highlighted in this figure is the a. diaphragm. c. larynx. b. bronchi. d. trachea.

d. trachea.

27. Which of the following is a characteristic of an organ used for gas exchange? a. limited surface area c. dry surfaces b. waterproofing layers d. very thin tissues

d. very thin tissues

10. Which of the following vitamins is NOT associated with building or maintaining bones and teeth? a. vitamin B12 c. vitamin D b. vitamin C d. vitamin E

d. vitamin E

6. Gases move from an area of ________ concentration to an area of ________ concentration.

high(er) low(er)