Experts in deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in ?yarding? areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.  This observation best illustrates which of the following principles about factors that limit distribution of organisms?

TLS Online TPP Program

#Question id: 12043

#Unit 7. System Physiology – Animal

Digestion of which of the following foodstuffs is impaired to the greatest extent in patients with achlorhydria?

TLS Online TPP Program

#Question id: 12277

#Unit 7. System Physiology – Animal

A 45-year-old man adds lots of high-fiber wheat and bran foods to his diet to reduce his cholesterol. He loses 30 lb on the new diet, but has undesirable side effects such as stomach cramps, flatulence, and diarrhea. His gastroenterologist diagnoses a syndrome called gluten-enteropathy or celiac sprue. Which of the following is decreased in this man?

TLS Online TPP Program

#Question id: 12218

#Unit 7. System Physiology – Animal

The control of gastric acid secretion in response to a meal involves several events that take place over a 4- or 5-hr period following the meal. These events include

(1) a decrease in the pH of the gastric contents,

(2) an increase in the rate of acid secretion,

(3) a decrease in the rate of acid secretion, and

(4) an increase in the pH of the gastric contents. Which of the following best describes

the correct temporal order of events over a 4- or 5-hr period following a meal?

TLS Online TPP Program

#Question id: 12217

#Unit 7. System Physiology – Animal

Cystic fibrosis is the most common cause of pancreatitis in children. Which of the following best explains the mechanism of cystic fibrosis–induced pancreatitis?

TLS Online TPP Program

#Question id: 12216

#Unit 7. System Physiology – Animal

Gastric emptying is regulated to ensure the chyme enters the duodenum at an appropriate rate. Which of the following factors promotes gastric emptying?

TLS Online TPP Program

#Question id: 12215

#Unit 7. System Physiology – Animal

Damage to the gastric mucosal barrier is a forerunner of gastric ulcer. Which of the following can both damage the gastric mucosal barrier and stimulate gastric acid secretion?