Deck 42: Animal Digestive Systems

Question 1

Which statement best describes why mechanical digestion, the process of breaking down large chunks of food into smaller pieces, is an important digestive process?

A) Because smaller pieces of food do not pass through the small intestine whereas larger pieces of food do
B) Because smaller pieces of food have more surface area for chemical digestion than do larger pieces of food
C) Because smaller pieces of food are easier to excrete than are larger pieces of food
D) Because smaller pieces of food are more easily stored in the stomach than are larger pieces of food

Answer 1

B

Question 2

It is important for pregnant women to consume folic acid supplements because ________.

A) the fetus is not able to acquire oxygen by breathing on its own
B) the fetus stores folic acid in high quantities
C) folic acid deprivation is associated with neural tube defects in a fetus
D) folic acid deprivation is a cause of heart abnormalities in a newborn

Answer 2

C

Question 3

Which of the following is an advantage of a complete digestive system?

A) It excludes the need for extracellular digestion.
B) It allows for specialized regions with specialized functions.
C) It allows extensive branching.
D) It facilitates intracellular digestion.

Answer 3

B

Question 4

Examine the digestive system structures in the figure. In which labeled structure is the rate of nutrient absorption the highest?

A) 1
B) 4
C) 5
D) 8

Question 5

Lysine is an essential amino acid for animals. An animal that lacked lysine in its diet ________.

A) would make lysine from other amino acids
B) could not make many necessary proteins
C) could not synthesize phospholipids
D) would be very healthy

Question 6

Which process does the large surface area in the intestine make more efficient?

A) secretion
B) absorption
C) filtration
D) temperature regulation

Question 7

The process by which digested dietary substances cross cell membranes to be used by the body is known as ________.

A) ingestion
B) digestion
C) hydrolysis
D) absorption

Question 8

Iodine deficiency in mammals will most likely result in ________.

A) decreased production of thyroid hormones
B) decreased enzyme function
C) weak bones
D) decreased muscle function

Question 9

Which of the following is a difference between vitamins and minerals?

A) Vitamins are involved in regulating enzyme activity, but minerals are not.
B) Vitamins are organic molecules, but minerals are inorganic molecules.
C) Vitamins are made by the animal, but minerals are obtained by an animal through dietary sources.
D) Vitamins are only obtained by digesting plants, whereas minerals are only obtained by digesting meat.

Question 10

Each of three groups of cyclists had a different diet: high-carbohydrate; a mix of carbohydrates, fat, and protein; or high in protein and fat. The blood glucose levels of the riders over a six-hour period after consuming each diet is shown in the accompanying graph. Which statement best summarizes the data in the graph?

A) Endurance is entirely related to diet.
B) Maintaining elevated blood sugar improves endurance.
C) An early 50 percent drop in blood glucose is associated with improved endurance.
D) Diet is not at all related to endurance.

Question 11

Which of the following statements is true regarding the digestive system in mammals?

A) all types of foods begin their enzymatic digestion in the esophagus
B) after leaving the oral cavity, the bolus enters the larynx
C) the epiglottis prevents swallowed food from entering the trachea
D) the trachea leads to the esophagus and then to the stomach

Question 12

Jasmine, a 36-year-old female, visits her personal care physician complaining of muscle cramps and reduced appetite. Which of the following options would a doctor likely advise her to do to reduce her symptoms?

A) eating a banana (high in potassium)
B) drinking a sports drink (high in sodium and chlorine)
C) eating dark green leafy vegetables (high in magnesium, iron, and calcium)
D) drinking water from the kitchen sink (high in fluoride)

Question 13

In a hydra, digestion is completed ________.

A) intracellularly
B) extracellularly
C) in the alimentary canal
D) in the gastrovascular cavity

Question 14

Termites are insects that eat a variety of dead plants, but they are most well-known for burrowing into wooden structures (including houses!) and eating the cellulose within the wood. What type of feeding mechanism do termites use?

A) Filter feeding
B) Fluid feeding
C) Bulk feeding
D) Substrate feeding

Question 15

Megaloblastic anemia results from a vitamin deficiency and causes abnormalities in red blood cell production and neurological issues. Megaloblastic anemia may be caused by a deficiency in which of the following vitamins?

A) vitamin A
B) vitamin B12
C) vitamin C
D) vitamin K

Question 16

Gastroliths are stones that are used by the digestive systems of some animals to perform mechanical digestion. Fossilized gastroliths have been found with dinosaur skeletons. What does this evidence suggest about the digestive systems of dinosaurs?

A) that dinosaurs had gastrovascular cavities
B) that dinosaurs had gizzards
C) that dinosaurs had crops
D) that dinosaurs had intestines

Question 17

Fat digestion yields fatty acids and glycerol, whereas protein digestion yields amino acids. Which of the following statements is true regarding these processes?

A) Both are catalyzed by the same enzyme
B) Both use water molecules when breaking bonds (hydrolysis)
C) Both require the presence of hydrochloric acid to lower the pH
D) Both initially occur in the mouth of an animal

Question 18

Ticks are parasites that obtain nutrients by ingesting blood from a host animal. Ticks would be classified as ________.

A) filter feeders
B) substrate feeders
C) fluid feeders
D) bulk feeders

Question 19

The following table shows the contents of a multivitamin supplement and its percentage of recommended daily values (% DV).

The most likely reason that some of the vitamins and minerals in this supplement are found at less than 100% is that ________.

A) it would be chemically impossible to add more
B) these vitamins and minerals are too large in size to reach 100%
C) it is too easy to overdose on minerals such as phosphorus and calcium
D) it is dangerous to ingest more than the recommended daily value of fat-soluble vitamins such as A and K

Question 20

Which of the following statements correctly describes peristalsis?

A) It is a process of fat emulsification in the small intestine.
B) It triggers voluntary control of the urethral sphincters regulating urination.
C) It causes the transport of nutrients to the liver through the hepatic portal vessel.
D) It results from smooth muscle contractions that move food along the esophagus.

Question 21

What converts pepsinogen to its active form in the stomach?

A) HCl
B) chief cells
C) high pH conditions
D) parietal cells

Question 22

What is the importance of the mucus that is released by salivary glands?

A) It aids in degradation of triglycerides to fatty acids and monoglycerides.
B) It assists with mechanical digestion by the teeth.
C) It contains hormonal molecules that stimulate the release of gastric juice by the stomach in anticipation of receipt of the contents of the mouth.
D) It consists of glycoproteins that make food slippery enough to slide easily through the esophagus.

Question 23

Which statement best describes why cells of the digestive system secrete proteolytic enzymes, such as pepsin, in their inactive forms?

A) These proteolytic enzymes, in active form, would digest the very tissues that synthesize them.
B) By secreting inactive enzymes, the catalytic activity of the enzymes is maintained for a longer time.
C) The stomach is too acidic to maintain these enzymes in their active form.
D) Inactive pepsin and trypsin are more easily transported across the cell membrane

Question 24

Which statement best explains why cattle able to survive on a diet consisting almost entirely of plant material?

A) because cattle are autotrophic
B) because cattle re-ingest their feces
C) because cattle manufacture all fifteen amino acids out of sugars in the liver
D) because cattle have cellulose-digesting, symbiotic microorganisms

Question 25

Constipation can result from the consumption of a substance that ________.

A) promotes water reabsorption in the large intestine
B) speeds up movement of material in the large intestine
C) decreases water reabsorption in the small intestine
D) increases chemical digestion in the small intestine

Question 26

Which of the following organs is correctly paired with its function?

A) stomach-fat digestion
B) large intestine-bile production
C) small intestine-polysaccharide digestion
D) pancreas-starch digestion

Question 27

The active ingredient orlistat acts to decrease the amount of fat that is absorbed by attaching to enzymes that digest fat. Which of the following is a potential target of orlistat?

A) salivary amylase
B) pepsidase
C) pancreatic lipase
D) secretin

Question 28

Which statement best describes what secretions of the parietal cells do upon activation by stomach acidity?

A) break peptide bonds of proteins in the stomach
B) slow the mechanical digestion of lipids in the stomach
C) initiate the chemical digestion of lipids in the stomach
D) delay digestion until the food arrives in the small intestine

Question 29

Which statement best explains how the absorption of fats differ from that of carbohydrates?

A) fat absorption primarily occurs in the stomach, whereas carbohydrates are absorbed from the small intestine
B) carbohydrates need to be emulsified before they can be digested, whereas fats do not
C) most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood
D) fats, but not carbohydrates, are digested by bacteria before absorption

Question 30

Which of the following correctly describes the function of chylomicrons?

A) to digest nucleic acids in the intestine
B) to break down carbohydrates in the mouth
C) to transport lipids from the intestine to adipose tissue
D) to move proteins across plasma membranes of cells

Question 31

A zoologist analyzes the jawbones of an extinct mammal and concludes that it was an herbivore. How did the zoologist most likely arrive at this conclusion?

A) they assessed the position of muscle attachment sites
B) they assessed the shape of the teeth
C) they assessed the size of the mouth opening
D) they assessed the number of bones in the neck

Question 32

Animals cannot produce enzymes to digest cellulose, yet many termite species consume cellulose from plant material as a main part of their diet. How do termites access the nutrients contained in cellulose?

A) Termites have specialized mouthparts to mechanically break down the cellulose.
B) The ingested plant material also contains enzymes for cellulose digestion.
C) Cellulose is digested intracellularly in the termite hindgut.
D) Mutualistic bacteria in the hindgut of the termite digest the cellulose into sugars.

Question 33

Nutrient-rich blood from the intestine is carried to the liver via which vessel?

A) lacteal vessels
B) hepatic portal artery
C) hepatic portal vein
D) lymphatic system

Question 34

If you found a vertebrate skull in the woods and the teeth were sharp and scissor-like, which type of food would you expect this animal to eat?

A) grass stems and leaves
B) animal flesh
C) plant nectar
D) animal blood

Question 35

Which statement best describes how stomach cells survive the acidity and protein-digesting activities in the stomach?

A) because they are surrounded by large colonies of H. pylori
B) because they are covered by a thick, mucous secretion and rapidly undergo active mitosis
C) because they are protected by a high level of secreted enzymes from chief cells
D) because they have cell walls impermeable to acid

Question 36

Over-the-counter medications for acid reflux or heartburn block the production of stomach acid. Which of the following cells are directly affected by this medication?

A) goblet cells
B) chief cells
C) parietal cells
D) smooth muscle cells

Question 37

Examine the digestive system structures in the figure. In which labeled structure are bacteria that produce vitamins found in the greatest concentration?

A) 3
B) 4
C) 5
D) 8

Question 38

Jahasz-Pocsine and co-workers found a correlation between gastric bypass surgery and neurological complications. In gastric bypass surgery, the stomach can be made smaller so as to hold less food and thus promote weight loss. Surgeons performed gastric bypass surgery on 150 patients at the University of Arkansas for Medical Sciences Neurology Clinic. Of the 150 patients, 26 experienced neurological complications related to the surgery. What is the most likely cause for the neurological complications?

A) sudden weight loss and caloric deficiency interfering with neurological function
B) nutrient (for example, vitamin and mineral) deficiencies
C) sloppy surgical technique of physicians performing the bypass surgery
D) infections following surgical intervention

Question 39

Examine the digestive system structures in the figure. In which labeled structure does the digestion of fats occur?

A) 3 only
B) 4 only
C) 1 only
D) 7 only

Question 40

Which group of animals are characterized by having a relatively long cecum?

A) carnivores
B) herbivores
C) autotrophs
D) omnivores

Question 41

If you put the following events in the order they occur in the human digestive system, which would be the third event in the series?

A) Cells in gastric pits secrete protons.
B) Pepsin activates pepsinogen.
C) HCl activates pepsinogen.
D) Partially digested food enters the small intestine.

Question 42

Which of the following is the fate of organic molecules that are absorbed in digestion but not immediately used for metabolism in an organism?

A) eliminated in the feces
B) stored as starch in the liver
C) stored as glycogen in the liver and muscles
D) oxidized and converted to ATP

Question 43

Which of the following molecules provides the greatest energy storage for animals?

A) proteins
B) minerals
C) carbohydrates
D) fats

Question 44

The mammalian trachea and esophagus both connect to the ________.

A) pharynx
B) stomach
C) large intestine
D) rectum

Question 45

In which digestive system organ does nearly all nutrient absorption occur?

A) stomach
B) small intestine
C) large intestine
D) pancreas

Question 46

Varsha is a paleontologist and discovers an intact mammalian skull with large, wide molars, and thin incisors only at the front of the jaw. The skull was lacking canines. What type of diet did this mammal likely eat?

A) prey animals including rodents, snakes, and frogs
B) leafy plants, trees, and shrubs
C) fish and molluscs
D) long grasses and small birds

Question 47

Which of the following happens to the production of insulin and glucagon in a healthy person after eating a carbohydrate-rich meal?

A) insulin levels increase and glucagon levels increase
B) insulin levels increase and glucagon levels decrease
C) insulin levels decrease and glucagon levels increase
D) insulin levels decrease and glucagon levels decrease

Question 48

If there is a strong genetic link for type II diabetes mellitus in your family, which option might you take to minimize your risk of developing the disorder?

A) monitor your blood glucose levels daily
B) take oral insulin daily
C) maintain a healthy weight, eat a balanced diet, and exercise
D) eat complex carbohydrates like starch instead of sweets

Question 49

Fat digestion yields fatty acids and glycerol. Protein digestion yields amino acids. Both digestive processes ________.

A) occur inside cells in most animals
B) add a water molecule to break bonds
C) require a low pH resulting from HCl production
D) consume ATP

Question 50

If you exercise, which stored fuel do you use first?

A) muscle proteins
B) liver glycogen and muscle glycogen
C) fat stored in adipose tissue
D) blood proteins

Question 51

In which organ does almost all enzymatic digestion of food occur?

A) stomach
B) small intestine
C) large intestine
D) pancreas

Question 52

A fasting animal whose energy needs exceed those provided in its diet will draw on its stored resources in which order?

A) fat, then glycogen, then protein
B) glycogen, then protein, then fat
C) liver glycogen, then muscle glycogen, then fat
D) muscle glycogen, then fat, then liver glycogen

Question 53

Which benefit do intestinal bacteria gain living in a mutualistic relationship with an animal?

A) The bacteria are provided with a regular source of nutrients.
B) Temperature is always regulated.
C) The bacteria can easily infect the animal's intestinal cells.
D) The bacteria can avoid the animal's immune system.

Question 54

Food being digested in the stomach is in a highly acidic environment. The pH of the small intestine is higher than that of the stomach. Which statement best explains why this occurs?

A) Secretin increases the flow of bicarbonate ions from the pancreas into the small intestine to neutralize the stomach acid.
B) Trypsinogen is activated, thus neutralizing the stomach acid.
C) Bile salts from the gallbladder neutralize the stomach acid.
D) When pepsinogen activates pepsin, one result is the neutralization of stomach acid in the stomach.

Question 55

When used appropriately by a patient, antibiotic treatment can effectively reduce bacteria populations and help fight infections. However, antibiotic treatments can have unintended effects. What is one concern when using antibiotics?

A) Antibiotics also damage animal cells, so they can be more harmful than a bacterial infection.
B) Antibiotics cause viruses to become more effective at infecting cells.
C) Each antibiotic is only effective against one type of bacteria, so effects on infection are limited.
D) Antibiotics may also kill the beneficial bacteria of the microbiome, thereby disrupting digestive health.

Question 56

Researchers sequenced bacterial DNA found in the stomachs of humans to analyze the human microbiome. They compared the microbiomes of stomachs from healthy humans to those of stomachs from humans infected by H. pylori. What can you conclude from these data?

A) H. pylori killed the other types of bacteria in the stomach.
B) The number of H. pylori bacteria in infected stomachs is larger than the number of Firmicutes bacteria in uninfected stomachs.
C) H. pylori infections result in reduced diversity of stomach bacteria.
D) Mechanical digestion is negatively affected in infected stomachs.

Question 57

If you were to jog 1 km a few hours after lunch, which stored fuel would you probably tap?

A) muscle proteins
B) muscle and liver glycogen
C) fat in the liver
D) fat in adipose tissue

Question 58

After surgical removal of the gallbladder, a person might need to limit his or her dietary intake of ________.

A) starch
B) protein
C) sugar
D) fat