Campbell Biology: Concepts and Connections, 8e (Reece et al.)
Chapter 21 Nutrition and Digestion
21.1 Multiple-Choice Questions
1) Which of the following statements regarding animals is false?
A) Animals that eat plants are called herbivores.
B) Animals that eat meat are called carnivores.
C) Animals that live in or on their food source and eat their way through it are called filter
feeders.
D) Animals that extract food particles suspended in the surrounding water are called fluid
feeders.
2) Most animals are
A) bulk feeders.
B) filter feeders.
C) suspension feeders.
D) fluid feeders.
3) Digestion is the
A) absorption of nutrients suspended in water.
B) conversion of glycogen to glucose.
C) breakdown of food into molecules small enough for the body to absorb.
D) churning of food in the stomach and intestine.
4) During which of the following stages of food processing is undigested material removed from
the digestive tract?
A) absorption
B) elimination
C) digestion
D) ingestion
5) What happens to nutrient macromolecules in an animal’s digestive tract?
A) They are absorbed whole and are then broken down into monomers within cells that
ultimately use them.
B) Proteins and nucleic acids are digested into monomers before absorption; energy-storage
macromolecules (starch and fat) are absorbed whole.
C) The digestive breakdown of macromolecules determines the monomers that are immediately
needed and therefore produced.
D) Nutrient macromolecules are digested into monomers before absorption.
6) Through digestion, polysaccharides are broken down into
A) fatty acids.
B) monosaccharides.
C) glycerols.
D) amino acids.
7) Through digestion, nucleic acids are broken down into
A) fatty acids.
B) glycerols.
C) nucleotides.
D) amino acids.
8) Which of the following organisms has a gastrovascular cavity?
A) hydra
B) earthworm
C) clam
D) bird
9) An animal digestive tract that consists of two openings (a mouth and anus) is called
A) an excretory system.
B) an alimentary canal.
C) an intestine.
D) an avian (bird) crop.
10) An alimentary canal is best defined as
A) the compartment in which an animal temporarily stores its food.
B) a digestive cavity in which food is churned and mixed.
C) a tube-shaped compartment for the transport, digestion, and absorption of food.
D) an organ designed for regulation of food passage.
11) The main function of an earthworm’s gizzard is to
A) moisten food.
B) store food.
C) absorb food.
D) grind food.
12) Which of the following choices lists the organs of the bird digestive system in the correct
order, from first to last contact with food material?
A) esophagus, stomach, gizzard, crop, intestine, anus
B) esophagus, gizzard, crop, stomach, intestine, anus
C) esophagus, crop, stomach, gizzard, intestine, anus
D) esophagus, crop, gizzard, stomach, intestine, anus
13) The main function of the hindgut in the grasshopper is to
A) reabsorb water and compact wastes.
B) digest food.
C) absorb nutrients.
D) absorb vitamins and pulverize food.
14) Nectarivores drink flower nectar that is a sugary sweet liquid. Nectarivores are an example of
________.
A) filter feeders
B) bulk feeders
C) fluid feeders
D) carnivores
15) Which of the following correctly lists the order of the parts of the human digestive system,
from first to last contact with food matter?
A) pharynx, oral cavity, esophagus, stomach, large intestine
B) oral cavity, pharynx, esophagus, stomach, small intestine, large intestine
C) esophagus, pharynx, stomach, small intestine, large intestine
D) oral cavity, esophagus, stomach, large intestine, small intestine
16) Smooth muscle propels food through the alimentary canal by a process called
A) ingestion.
B) diffusion.
C) active transport.
D) peristalsis.
17) Regulation of the passage of food from the stomach is accomplished by
A) peristalsis.
B) nutrient absorption.
C) sphincters.
D) the stomach lining.
18) Digestion begins in the
A) small intestine.
B) oral cavity.
C) esophagus.
D) stomach.
19) What is the name given to the starch-digesting enzyme secreted by salivary glands?
A) bile salts
B) lipase
C) pepsin
D) amylase
20) Human saliva performs all of the following functions except
A) neutralizing food acids.
B) controlling bacterial populations.
C) hydrolyzing starch.
D) hydrolyzing proteins.
21) The tongue does all of the following except
A) taste food.
B) shape food into a ball called a bolus.
C) secrete saliva.
D) push food into the pharynx.
22) The epiglottis is a
A) muscle that moves the esophagus into line with the pharynx during swallowing.
B) muscle that moves the trachea out of line with the pharynx during swallowing.
C) flap of cartilage that flips down to cover the entry to the trachea during swallowing.
D) muscle sphincter that closes off the entry to the trachea during swallowing.
23) The structure of the esophagus fits its function in that
A) it can direct food to the lungs or stomach.
B) it has smooth muscle for peristalsis.
C) it is regulated by contractions in the pharynx.
D) its length determines the volume of food an animal can ingest.
24) The Heimlich maneuver is performed to forcibly
A) elevate the diaphragm.
B) depress the diaphragm.
C) squeeze the ribs.
D) compress the intestines.
25) The mucus-producing cells that line the stomach
A) increase the surface of the stomach for faster digestion.
B) stimulate production of hydrochloric acid.
C) lubricate and protect the stomach lining.
D) move food upward in the stomach to prolong digestion.
26) The secretory parietal cells of the stomach are responsible for producing
A) mucus.
B) pepsin.
C) hydrochloric acid.
D) lactic acid.
27) Which of the following mechanisms helps keep the stomach lining in place despite the
destructive force of gastric juice?
A) digestion of protein by pepsin
B) secretion of acid-neutralizing compounds
C) generation through mitosis of new cells to replace the stomach lining
D) protection of the cells of the stomach-lining by parietal cells
28) The stomach mixes food with secretions of the stomach wall to form
A) gastric juice.
B) a parietal bolus.
C) gastrin.
D) chyme.
29) The function of the sphincter between the stomach and small intestine is to
A) retain chyme in the stomach until pepsin digestion is complete.
B) periodically release chyme into the small intestine in squirts.
C) release bile into the duodenum when chyme is present.
D) release pancreatic secretions into the duodenum when chyme is present.
30) Heartburn is usually caused by the
A) secretion of acid by the lining of the lower esophagus.
B) reflux of chyme from the stomach into the lower esophagus.
C) retention of food at the bottom of the esophagus by a sphincter that is reluctant to open.
D) irritation of the lower esophagus by substances in spicy food.
31) When the wall of the stomach cannot protect the organ from the effects of digestion, the
result is
A) heartburn.
B) peristalsis.
C) nausea.
D) a gastric ulcer.
32) Most gastric ulcers are caused by
A) overuse of aspirin and/or ibuprofen.
B) excessive mental stress.
C) bacteria.
D) overconsumption of alcohol.
33) In the digestive system, most nutrient absorption occurs in the
A) stomach.
B) pancreas.
C) small intestine.
D) large intestine.
34) Epithelial cells lining the intestine have surface projections that increase the rate of nutrient
absorption. These projections are called
A) villi.
B) cilia.
C) microvilli.
D) parietal cells.
35) What is the main digestive function of the pancreas?
A) to produce digestive enzymes and bile salts
B) to produce digestive enzymes and an alkaline solution
C) to produce bicarbonate-containing mucus
D) to aid in the control of cholesterol
36) Which of the following is important in the digestion of lipids?
A) pepsin
B) amylase
C) bile salts
D) trypsin
37) Lack of exercise and activity can be one of several reasons a person might become
constipated, or be unable to have regular bowel movements. Which of the four stages of food
processing is directly affected in this situation?
A) ingestion
B) digestion
C) absorption
D) elimination
38) Bile produced in the liver is stored in the ________ before entering the intestine.
A) pancreas
B) blood
C) gallbladder
D) common bile duct
39) Which enzyme breaks large polypeptides into smaller polypeptides?
A) amylase
B) lipase
C) lactase
D) chymotrypsin
40) Which of the following nutrients is digested only after it reaches the small intestine?
A) fat
B) protein
C) starch
D) polypeptide
41) Nutrients absorbed by the intestines move directly to the liver, which
A) converts the nutrients into monomers.
B) converts excess glucose to glycogen.
C) manages the amount of glucose that is converted to amylase.
D) converts glucose to alcohol.
42) Reabsorption of water is a major function of the
A) esophagus.
B) colon.
C) rectum.
D) appendix.
43) Altogether, the body secretes about 7 liters of water into the alimentary canal each day.
About what percentage of this water gets reabsorbed?
A) 30%
B) 50%
C) 75%
D) 90%
44) Which of the following statements regarding animal digestive systems is false?
A) We expect that an herbivore will have a longer alimentary canal than a carnivore of similar
body size.
B) Meat is more difficult to digest than vegetable matter because of its protein content.
C) Many herbivorous animals have cellulose-digesting microbes in their colon and cecum.
D) When cows chew their cud, it helps to soften and break down plant fibers, making these more
accessible to digestion by microbes.
45) Lions are not always successful hunters and may go days between meals. What evolutionary
adaptation helps the lion survive periods of famine?
A) formation of a two-chambered stomach
B) an extended cecum
C) an expandable stomach
D) a rich microbial flora in the colon
46) Interestingly, most herbivorous animals do not have the ability to digest the cellulose in
plants. However, in the absence of this ability, a mechanism has evolved that allows them to
survive despite eating only plant matter, namely,
A) production of saliva containing amylase.
B) digestion by symbiotic microorganisms.
C) avoidance of plants containing cellulose.
D) converting cellulose to other carbohydrates.
47) Which of the following digestive system structures is greatly expanded in size in koalas,
resulting in a very large surface area for prokaryotes to digest plant material?
A) stomach
B) rumen
C) cecum
D) gall bladder
48) All animals must obtain ________ from outside sources.
A) preformed ATP
B) fuel to power body activities
C) enzymes
D) chyme
49) Which of the following statements regarding metabolism is false?
A) The basal metabolic rate is the amount of energy an animal needs just to stay alive; it does not
include the energy needed for activities.
B) Cells usually use carbohydrates and fats as fuel sources.
C) Humans store some extra energy in the form of glycogen reserves in the pancreas and spleen.
D) The average basal metabolic rate is 1300-1500 kcal per day for females and 1600-1800 kcal
per day for males.
50) The rate of energy consumption by an animal is called
A) metabolism.
B) digestion.
C) metabolic rate.
D) glycolysis.
51) Organisms suffering from malnutrition may have a diet deficient in
A) one or more essential nutrients.
B) bile and acids needed for digestion.
C) digestive enzymes.
D) water.
52) A material that must be ingested in preassembled form because the animal cannot synthesize
it is
A) an end product.
B) adenosine triphosphate.
C) glucose.
D) an essential nutrient.
53) Essential fatty acids, which are required in the human diet, are
A) those fatty acids that humans are unable to synthesize.
B) the fatty acids that humans can synthesize from simpler molecules.
C) the fatty acids used in the construction of the phospholipids of cell membranes.
D) stored in the gallbladder.
54) The essential amino acids
A) must be obtained from the food we eat.
B) are found only in green, leafy vegetables.
C) are essential as an energy source.
D) are required for making nucleic acids.
55) Vegetarians who rely upon a single type of plant food
A) may become severely dehydrated.
B) run the risk of depleting their liver of glycogen.
C) are soon unable to produce sufficient quantities of bile.
D) may become protein-deficient.
56) Which of the following vitamins is fat-soluble and, consequently, can be stored in body fat?
A) biotin
B) pantothenic acid
C) niacin
D) K
57) Which of the following statements regarding vitamins is true?
A) They are simple inorganic compounds.
B) They must be ingested in large quantities.
C) They can serve as coenzymes or parts of coenzymes.
D) They are major sources of dietary calories.
58) Which of the following choices correctly pairs a mineral with one of its major functions in
the body?
A) calcium, used in amino acid metabolism
B) phosphorus, maintaining water balance
C) iron, component of the nucleic acid backbone
D) sodium, maintaining water balance in cells
59) If a person on a fad diet experiences muscle cramps, a physician would suspect that this
individual is likely suffering from a deficiency of
A) table salt.
B) iodine.
C) iron.
D) calcium.
60) The minimal amount of nutrients needed every day by healthy people to prevent nutrient
deficiencies is called the
A) RDA, Recommended Dietary Allowance.
B) minimum mineral requirements.
C) minimum vitamin requirements.
D) varied diet of minerals and vitamins.