$$O = \frac{\text{moles of solute}}{\text{liters of solution}}$$

Question 1

Which of the following best describes the main function of the endocrine system in animals?

Accepted Answer

It secretes hormones into the bloodstream to regulate physiological processes.

Question 2

A freshwater fish is placed in a tank with seawater. Which of the following physiological challenges will it most likely face?

Accepted Answer

It will lose water by osmosis and risk dehydration.

Question 3

Which hormone is responsible for lowering blood glucose levels, and which organ produces it?

Accepted Answer

Insulin; pancreas

Question 4

Which of the following is an example of negative feedback in homeostasis?

Accepted Answer

Secretion of insulin in response to high blood glucose to lower glucose levels

Question 5

Which of the following equations correctly represents the osmolarity ($$O) of a $$solution?

Accepted Answer

$$O = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 6

Which structure in the vertebrate excretory system is primarily responsible for filtration of blood?

Accepted Answer

Bowman's capsule and glomerulus

Question 7

A marine fish actively drinks seawater and excretes excess salts through its gills. What is the main reason for this adaptation?

Accepted Answer

To prevent water loss in a hypertonic environment

Question 8

Which of the following best explains why endotherms require more food than ectotherms of similar size?

Accepted Answer

Endotherms use more energy to maintain a constant internal temperature.

Question 9

Which process in the nephron is responsible for reclaiming valuable solutes from the filtrate?

Accepted Answer

Reabsorption

Question 10

A patient has a mutation that prevents the production of antidiuretic hormone (ADH). Which symptom would you expect?

Accepted Answer

Excessive loss of water in urine (dilute urine)

Question 11

Which of the following best describes the difference between endocrine and exocrine glands?

Accepted Answer

Endocrine glands secrete hormones into the bloodstream; exocrine glands secrete products into ducts leading to external environments.

Question 12

Which hormone is secreted by the adrenal medulla and is responsible for the 'fight or flight' response?

Accepted Answer

Epinephrine

Question 13

Which of the following is a correct sequence of events in a simple endocrine pathway regulating blood pH in the duodenum?

Accepted Answer

Acidic chyme enters duodenum → hormone released → pancreas secretes bicarbonate → pH increases

Question 14

Which of the following best explains why a lizard basks in the sun in the morning and seeks shade at midday?

Accepted Answer

To maintain homeostatic body temperature through behavioral adjustments

Question 15

Which of the following is a correct statement about the evolutionary function of thyroid hormone?

Accepted Answer

It stimulates tail resorption during metamorphosis in frogs.

Question 16

Which of the following best describes the role of the loop of Henle in the nephron?

Accepted Answer

It creates a concentration gradient in the medulla to allow water reabsorption.

Question 17

Which of the following is a primary nitrogenous waste product in mammals, and why is it advantageous?

Accepted Answer

Urea; it is less toxic and conserves water compared to ammonia.

Question 18

Which of the following best describes the effect of epinephrine on different target tissues?

Accepted Answer

It increases blood flow to muscles and decreases blood flow to the digestive system.

Question 19

Which of the following is a correct description of the process of secretion in the nephron?

Accepted Answer

It is the addition of nonessential solutes and wastes from the blood into the filtrate.

Homeostasis, Endocrine Signaling, Osmoregulation, and Temperature Regulation

Study Guide - Practice Questions