Question 1

Which of the following best describes the main osmoregulatory challenge faced by freshwater fish?

Accepted Answer

They gain water by osmosis and must excrete large volumes of dilute urine.

Question 2

Which of the following is a correct pairing of a hormone with its primary function?

Accepted Answer

Parathyroid hormone: increases blood calcium levels

Question 3

A patient is diagnosed with an autoimmune disorder in which their immune system attacks their own pancreatic beta cells. Which hormone is most likely to be deficient as a result?

Accepted Answer

Insulin

Question 4

Which of the following best explains why marine bony fish must actively excrete salt through their gills?

Accepted Answer

They live in a hyperosmotic environment and gain salts by diffusion.

Question 5

Which of the following is NOT a function of the innate immune system?

Accepted Answer

Production of antibodies by B cells

Question 6

A person is exposed to a virus for the first time. Which immune response is primarily responsible for the initial defense?

Accepted Answer

Innate immune response

Question 7

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

Accepted Answer

It reabsorbs water and concentrates urine by creating a salt gradient in the medulla.

Question 8

Which of the following best explains why action potentials travel in only one direction along an axon?

Accepted Answer

Voltage-gated sodium channels become inactivated immediately after opening, creating a refractory period.

Question 9

Which of the following scenarios best illustrates negative feedback in the endocrine system?

Accepted Answer

A rise in blood glucose stimulates insulin release, which lowers blood glucose and inhibits further insulin release.

Question 10

Which of the following best describes the difference between the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The CNS includes the brain and spinal cord, while the PNS includes all nerves outside the CNS.

Question 11

Which of the following is a correct sequence of events in the humoral immune response?

Accepted Answer

Antigen presentation → activation of helper T cells → activation of B cells → production of antibodies

Question 12

Which of the following best explains why a person who has recovered from chickenpox is usually immune to future infections by the same virus?

Accepted Answer

The adaptive immune system has memory B and T cells specific to the virus.

Question 13

Which of the following best describes the function of dendritic cells in the immune system?

Accepted Answer

They engulf pathogens and present antigens to T cells.

Question 14

A person is experiencing muscle weakness and fatigue due to low levels of acetylcholine at the neuromuscular junction. Which process is most directly affected?

Accepted Answer

Stimulation of muscle contraction

Question 15

Which of the following best describes the role of the hypothalamus in the endocrine system?

Accepted Answer

It produces releasing hormones that regulate the anterior pituitary gland.

Question 16

Which of the following is a correct description of the function of the sodium-potassium pump in neurons?

Accepted Answer

It actively transports sodium out of the cell and potassium into the cell, maintaining the resting membrane potential.

Question 17

Which of the following best explains why the adaptive immune response is slower upon first exposure to a pathogen compared to subsequent exposures?

Accepted Answer

Memory cells are not yet present during the first exposure.

Question 18

Which of the following best describes the effect of aldosterone on kidney function?

Accepted Answer

It increases sodium reabsorption and water retention, raising blood pressure.

Question 19

Which of the following is a correct statement about the difference between white matter and gray matter in the nervous system?

Accepted Answer

White matter consists mainly of myelinated axons, while gray matter consists of neuron cell bodies and dendrites.

Question 20

A patient is given a drug that blocks the action of antidiuretic hormone (ADH). What is the most likely effect on the patient's urine output?

Accepted Answer

Urine output will increase and become more dilute.

Study Guide: Animal Osmoregulation, Immune System, and Endocrine System

Study Guide - Practice Questions

Study Guide - Flashcards