Question 1

Which of the following occurs during suction feeding in fishes?

Accepted Answer

Suction feeding in fishes involves expanding the buccal cavity to create negative pressure, which draws water and prey into the mouth. The prey is then trapped in the mouth and broken up by pharyngeal jaws in the pharynx.

Question 2

One of the effects of the hormone secretin is to stimulate the release of bicarbonate ions into the duodenum, which neutralizes the acid that enters the duodenum with food from the stomach. One consequence of neutralizing the pH in the intestine is that:

Accepted Answer

Enzymes that catalyze the hydrolysis of carbohydrates require a neutral or slightly alkaline environment to be active. Neutralizing the pH in the intestine allows these enzymes to function optimally and continue breaking down carbohydrates that were partially hydrolyzed in the stomach.

Question 3

Food poisoning can sometimes result from ingestion of bacteria called Salmonella in meats and eggs. When Salmonella is ingested, it multiplies in the lumen of the gut, where it can lead to inflammation of the gut lining and symptoms like diarrhea and abdominal cramps. Occasionally, the bacteria enter the bloodstream. The route the bacteria take to get to the bloodstream is:

Accepted Answer

The answer of Food poisoning can sometimes result from ingestion...

Question 4

E. coli resides in our small and large intestines and, in the process of nourishing itself by digesting the "leftovers" it finds in our digestive tracts, provides us with:

Accepted Answer

E. coli in our intestines produces vitamin K, which is important for blood clotting and bone health.

Question 5

Which of the following is NOT an example of suction feeding?

Accepted Answer

Trapping prey with blades of baleen is filter feeding, not suction feeding. Suction feeding involves creating a vacuum to draw in food, which is not the mechanism used by baleen whales.

Question 6

Which of the following is NOT a specialized function of one or more regions of the digestive tract?

Accepted Answer

Aerobic metabolism is not a specialized function of the digestive tract. Rather, it is a process that occurs within cells during cellular respiration. The specialized functions of the digestive tract include food storage, chemical breakdown, absorption of nutrients, and elimination of waste products.

Question 7

Most nutrient absorption takes place in the:

Accepted Answer

The majority of nutrient absorption occurs in the small intestine, specifically in the duodenum (first part) and jejunum (second part). The large intestine primarily absorbs water and electrolytes, while the stomach plays a role in breaking down food but does not absorb significant amounts of nutrients. The pancreas and liver secrete enzymes and bile, respectively, to aid in digestion but do not directly absorb nutrients.

Question 8

The ability to digest lactose into adulthood results from either of two separate mutations that evolved independently of each other in different human populations. These two mutations are an example of:

Accepted Answer

The answer of The ability to digest lactose into adulthood...

Question 9

Which layer of the digestive tract houses the small blood vessels into which nutrients are absorbed?

Accepted Answer

The mucosa is the innermost layer of the digestive tract, containing the epithelial cells responsible for nutrient absorption.

Question 10

Which of the following is NOT a correct pairing of tooth type and function?

Accepted Answer

Incisors are for piercing, canines are for ripping and tearing, premolars are for shearing, and molars are for grinding.

Question 11

Which of the following statements is NOT true?

Accepted Answer

Animals that use suspension filter feeding are not all herbivores. Some, like baleen whales, filter feed on small crustaceans and planktonic animals, while others, like scallops, filter feed on phytoplankton and other small organisms.

Question 12

Glucose enters the epithelial cells of the small intestine against its concentration gradient. Select the BEST explanation from the following.

Accepted Answer

Glucose is co-transported with Na+ ions, which move down their concentration gradient into the cell. This type of transport is called secondary active transport or co-transport.

Question 13

Because most herbivores do not produce cellulase, they have specialized compartments in their digestive tracts that:

Accepted Answer

Herbivores rely on symbiotic bacteria in their digestive systems to produce cellulase, an enzyme necessary for breaking down cellulose in plant cell walls, which the animals themselves cannot produce.

Question 14

A mammalian skull found in the forest has incisors, small canines, and many large premolars and molars with prominent surface ridges. Based on this information, what conclusions can be drawn about the feeding behavior of this organism?

Accepted Answer

The answer of A mammalian skull found in the forest...

Question 15

Which of the following statements is TRUE of the midgut?

Accepted Answer

The midgut includes the small intestine, where most nutrient absorption occurs. The large intestine is part of the hindgut, not the midgut. The midgut is not primarily for food and nutrient storage; that's more associated with the stomach's temporary storage function and the large intestine's role in water absorption and feces formation. Glucose absorption in the small intestine (midgut) involves active transport rather than passive diffusion.

Question 16

Bile, which aids in the digestion of fat, is stored in the _____.

Accepted Answer

The answer of Bile, which aids in the digestion of...

Question 17

What is the function of the temporomandibular joint?

Accepted Answer

The temporomandibular joint is responsible for the movement of the jaws, allowing them to open and close. It is the joint that connects the jawbone to the skull and is essential for actions like speaking, chewing, and swallowing. Therefore, option A is the correct answer. The other options are not accurate as the temporomandibular joint does not primarily function to increase the strength or speed of the jaws or help consume large prey items.

Question 18

One of the hormones not mentioned in the text is GIP (glucose-dependent insulin trophic peptide), which stimulates the secretion of insulin. It is secreted by cells of the duodenum in response to the presence of glucose. Its secretion and action on insulin production is an example of a:

Accepted Answer

GIP's role in stimulating insulin secretion in response to glucose is a negative feedback mechanism, as it helps to reduce blood glucose levels back towards a set point, rather than amplifying the response.

Question 19

Rabbits produce two types of droppings: fecal pellets, which are waste products of digestion, and cecotropes, which they re-ingest. Ruminants do not re-ingest any feces. What is the difference between the two that requires re-ingestion by rabbits, not cows?

Accepted Answer

Rabbits are hindgut fermenters, meaning that the fermentation of food occurs in the cecum, which is located after the small intestine. Nutrients are absorbed in the cecum and the resulting cecotropes are re-ingested to extract additional nutrients. Ruminants, on the other hand, are foregut fermenters, meaning that the fermentation of food occurs in the rumen, which is located before the true stomach. The products of digestion are absorbed in the small intestine, and there is no need for them to re-ingest feces.

Question 20

The duct that connects the pancreas to the duodenum can sometimes become blocked. What is the result?

Accepted Answer

When the duct that connects the pancreas to the duodenum becomes blocked, the digestive enzymes produced by the pancreas back up into the pancreas itself. This can lead to inflammation of the pancreas or pancreatitis, which can be a serious and potentially life-threatening condition. Digestion is disrupted because without the release of pancreatic enzymes, food is not properly broken down in the duodenum, which can cause malabsorption and other digestive problems.

Quiz 40: Animal Metabolism, Nutrition, and Digestion