General Biology Chapter 20

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.

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

a. The Z disks move closer together.

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.

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

a. bone.

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

a. protein.

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.

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

a. the skin

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.

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.

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.

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.

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.

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.

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

b. capillaries.

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

b. in a muscle that bends the knee

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

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.

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

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

b. smooth muscle.

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.

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.

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 b. vitamin K c. vitamin A d. vitamin C

b. vitamin K

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

b. vitamins

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.

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.

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.

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.

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

c. gallbladder.

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

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.

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

c. the large intestine

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.

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.

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

d. D

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.

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.

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

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

d. a smooth surface

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.

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

d. appendicular; motion

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 b. proteins c. vitamins d. fats

d. fats

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.

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 b. the ligaments around the knee c. spongy bone d. the synovial sac

d. the synovial sac

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

d. vitamin E