Question 1

Which of the following best describes the main function of osmoregulation in animals?

Accepted Answer

Regulating the balance of water and solutes to ensure proper cell function.

Question 2

Freshwater fish are hyperosmotic to their environment. What is a consequence of this condition?

Accepted Answer

They gain water from their environment and must excrete large amounts of dilute urine.

Question 3

Which nitrogenous waste is the most energetically expensive to produce but least toxic?

Accepted Answer

Uric acid

Question 4

What is the correct order of filtrate flow through the nephron tubule?

Accepted Answer

Bowman's capsule → Proximal tubule → Loop of Henle → Distal tubule → Collecting duct

Question 5

Which structure in the nephron is primarily responsible for the reabsorption of water, ions, and nutrients?

Accepted Answer

Proximal tubule

Question 6

Why does the glomerulus have a much higher hydrostatic pressure (55 mm Hg) compared to other capillaries in the body (15 mm Hg)?

Accepted Answer

To ensure efficient filtration of blood plasma into Bowman's capsule.

Question 7

Which of the following best explains why the descending limb of the loop of Henle allows water to leave but not solutes?

Accepted Answer

It contains aquaporins but lacks ion channels.

Question 8

What is the main effect of antidiuretic hormone (ADH) on the collecting duct?

Accepted Answer

It increases the permeability of the collecting duct to water, resulting in more concentrated urine.

Question 9

Which of the following is a function of the kidney besides filtration?

Accepted Answer

Production of erythropoietin to stimulate red blood cell formation.

Question 10

Which mechanism is used by insects to excrete nitrogenous wastes?

Accepted Answer

Malpighian tubules

Question 11

What is the primary reason terrestrial animals convert ammonia to urea or uric acid?

Accepted Answer

To conserve water and reduce toxicity.

Question 12

Which of the following best describes the function of microvilli in the proximal tubule?

Accepted Answer

Increase surface area for reabsorption of nutrients and water.

Question 13

Which of the following is the correct order of blood flow through the kidney?

Accepted Answer

Renal artery → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries → renal vein

Question 14

Which hormone increases sodium reabsorption in the distal tubule and collecting duct, thereby increasing blood pressure?

Accepted Answer

Aldosterone

Question 15

A patient is given a diuretic medication. What is the expected effect on their urine output and why?

Accepted Answer

Urine output will increase because diuretics block ADH, reducing water reabsorption.

Question 16

Which of the following best explains why marine bony fish drink seawater and excrete concentrated urine?

Accepted Answer

They are hypoosmotic to their environment and lose water by osmosis.

Question 17

Which process in the nephron is responsible for moving substances such as drugs and toxins from the blood into the filtrate?

Accepted Answer

Secretion

Question 18

What is the main advantage of the countercurrent multiplier system in the loop of Henle?

Accepted Answer

It allows the kidney to produce urine that is more concentrated than blood plasma.

Question 19

Which excretory structure is found in annelids and is responsible for filtering coelomic fluid?

Accepted Answer

Nephridia

Question 20

A mutation causes the loss of aquaporin channels in the collecting duct. What is the most likely physiological consequence?

Accepted Answer

The individual will produce large volumes of dilute urine and risk dehydration.

Osmoregulation and Excretion (Chapter 44): Study Notes

Study Guide - Practice Questions