Question 1

Which of the following best describes the difference between negative and positive feedback mechanisms in homeostasis?

Accepted Answer

Negative feedback reverses a change to maintain stability, while positive feedback enhances the original change.

Question 2

A patient is unable to produce sufficient antidiuretic hormone (ADH). Which organ system is primarily affected, and what is a likely consequence?

Accepted Answer

Urinary system; excessive water loss in urine

Question 3

Which of the following equations correctly represents the chemical reaction for cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2 ightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 4

A patient presents with muscle weakness and fatigue. Blood tests reveal low calcium levels. Which hormone is most likely deficient?

Accepted Answer

Parathyroid hormone (PTH)

Question 5

Which of the following best explains why red blood cells placed in a hypotonic solution swell and may burst?

Accepted Answer

Water moves into the cell by osmosis due to a higher solute concentration inside the cell.

Question 6

Which of the following is a function of the sodium-potassium pump ($$\mathrm{Na}^+/\mathrm{K}^+-$$ATPase) in neurons?

Accepted Answer

It maintains the resting membrane potential by actively transporting $$3\ \mathrm{Na}^+$$ out and $$2\ \mathrm{K}^+$$ into the cell.

Question 7

A person suffers a stroke that damages the left primary motor cortex. Which of the following symptoms is most likely?

Accepted Answer

Paralysis of voluntary movements on the right side of the body

Question 8

Which of the following best describes the sliding filament theory of muscle contraction?

Accepted Answer

Myosin heads bind to actin, pulling the thin filaments toward the center of the sarcomere.

Question 9

Which of the following is the correct sequence of events in the transmission of a nerve impulse across a chemical synapse?

Accepted Answer

Action potential arrives, calcium channels open, neurotransmitter released, neurotransmitter binds to postsynaptic receptors

Question 10

A patient with type 1 diabetes mellitus is given an injection of insulin. Which of the following best describes the effect on blood glucose levels?

Accepted Answer

Blood glucose levels decrease as glucose uptake by cells increases.

Question 11

Which of the following best explains why the left ventricle of the heart has a thicker wall than the right ventricle?

Accepted Answer

It pumps blood at a higher pressure to the entire body.

Question 12

Which of the following is a correct description of the function of the nephron in the kidney?

Accepted Answer

It filters blood, reabsorbs needed substances, and secretes wastes into urine.

Question 13

A person is exposed to a cold environment. Which of the following physiological responses is most likely to occur to maintain body temperature?

Accepted Answer

Shivering and vasoconstriction of cutaneous blood vessels

Question 14

Which of the following best describes the role of surfactant in the lungs?

Accepted Answer

It decreases surface tension, preventing alveolar collapse.

Question 15

Which of the following is a correct pairing of a digestive enzyme and its substrate?

Accepted Answer

Lipase – lipids

Question 16

A patient has a blood pH of 7.1. Which of the following best describes this condition and a likely physiological consequence?

Accepted Answer

Acidosis; decreased enzyme activity

Question 17

Which of the following best explains the difference between the somatic and autonomic nervous systems?

Accepted Answer

The somatic nervous system controls voluntary skeletal muscles, while the autonomic controls involuntary smooth and cardiac muscles.

Question 18

Which of the following best describes the function of osteoclasts in bone tissue?

Accepted Answer

They break down bone matrix, releasing calcium into the blood.

Question 19

A person is unable to distinguish between sweet and salty tastes. Which cranial nerves are most likely affected?

Accepted Answer

Cranial nerves VII and IX

Comprehensive Study Guide for Anatomy & Physiology (BIOLOGY 109)

Study Guide - Practice Questions