Question 1

Which of the following best explains why steroid hormones, such as cortisol, can directly affect gene expression in target cells?

Accepted Answer

Steroid hormones are lipid-soluble and can cross the plasma membrane to bind intracellular receptors.

Question 2

A patient presents with an enlarged thyroid gland (goiter) and symptoms of hypothyroidism. Which of the following is the most likely cause?

Accepted Answer

Iodine deficiency leading to decreased thyroid hormone synthesis and increased TSH stimulation.

Question 3

Which of the following best describes the difference between the anterior and posterior pituitary glands?

Accepted Answer

The anterior pituitary produces hormones in response to releasing and inhibiting hormones from the hypothalamus, while the posterior pituitary stores and releases hormones made in the hypothalamus.

Question 4

Which hormone is responsible for stimulating ovulation in the ovarian cycle, and what is the mechanism of its action?

Accepted Answer

Luteinizing hormone (LH); a surge in LH causes the mature follicle to release an egg.

Question 5

A person is exposed to a sudden threat, triggering the 'fight-or-flight' response. Which hormone is primarily responsible for the immediate physiological changes, and what is one effect on the body?

Accepted Answer

Epinephrine; dilates blood vessels in skeletal muscles.

Question 6

Which of the following best explains why the testes are located outside the abdominal cavity in many mammals?

Accepted Answer

To maintain a temperature lower than body temperature, which is necessary for proper spermatogenesis.

Question 7

Which of the following is a key difference between spermatogenesis and oogenesis in humans?

Accepted Answer

Spermatogenesis results in four functional sperm, while oogenesis results in one functional egg and polar bodies.

Question 8

A patient has low blood calcium levels. Which hormone is likely to be secreted in higher amounts to restore homeostasis, and what is its effect?

Accepted Answer

Parathyroid hormone (PTH); increases calcium release from bones and reabsorption in the kidneys.

Question 9

Which of the following best describes the mechanism by which water-soluble hormones, such as epinephrine, exert their effects on target cells?

Accepted Answer

They bind to membrane receptors, activating second messenger systems such as cyclic AMP.

Question 10

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

Accepted Answer

Rising blood glucose stimulates insulin release, which lowers blood glucose and reduces further insulin secretion.

Question 11

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

Accepted Answer

The refractory period prevents the region of the membrane that just fired from immediately firing again.

Question 12

A neuron receives two excitatory postsynaptic potentials (EPSPs) in rapid succession at the same synapse. What is this phenomenon called, and what is its effect?

Accepted Answer

Temporal summation; the EPSPs add together, increasing the likelihood of reaching threshold.

Question 13

Which of the following is a function of oligodendrocytes in the central nervous system?

Accepted Answer

Forming myelin sheaths around axons.

Question 14

Which neurotransmitter is most commonly associated with excitatory signaling in both invertebrates and vertebrates?

Accepted Answer

Acetylcholine

Question 15

Which brain structure is primarily responsible for connecting the left and right cerebral hemispheres, allowing communication between them?

Accepted Answer

Corpus callosum

Question 16

A person suffers a stroke that damages the occipital lobe of the cerebral cortex. Which primary function is most likely to be affected?

Accepted Answer

Vision

Question 17

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

Accepted Answer

It receives information from the nervous system and initiates endocrine responses by releasing hormones that control the pituitary gland.

Question 18

Which of the following is a correct sequence for the passage of a sperm cell from its site of production to the outside of the body?

Accepted Answer

Testis → Epididymis → Vas deferens → Urethra

Question 19

Which of the following best explains why the same hormone, such as epinephrine, can have different effects on different tissues?

Accepted Answer

Different tissues have different receptors or signal transduction pathways for the same hormone.

Unit 6 Study Guide: Hormones, Reproduction, and Nervous Systems

Study Guide - Practice Questions

Study Guide - Flashcards