Question 1

Which of the following best explains why only certain cells respond to a particular hormone, even though the hormone circulates throughout the entire body?

Accepted Answer

Only target cells have specific receptors for that hormone.

Question 2

A patient is given a drug that blocks the action of G protein-coupled receptors. Which hormone's effect would be most directly impaired by this drug?

Accepted Answer

Epinephrine

Question 3

Which of the following is a correct sequence of events in a simple neuroendocrine pathway, such as milk release in mammals?

Accepted Answer

Stimulus → Sensory neuron → Neurosecretory cell → Neurohormone release → Target cell response

Question 4

Which of the following best describes the difference between water-soluble and lipid-soluble hormones in terms of their mechanism of action?

Accepted Answer

Water-soluble hormones bind to cell-surface receptors, while lipid-soluble hormones bind to intracellular receptors.

Question 5

A person has a tumor that causes excessive secretion of parathyroid hormone (PTH). Which of the following symptoms would most likely be observed?

Accepted Answer

Elevated blood calcium levels due to increased bone resorption

Question 6

Which hormone is primarily responsible for the fight-or-flight response, and what is one of its main effects on the body?

Accepted Answer

Epinephrine; increases the rate of glycogen breakdown in the liver

Question 7

Which of the following is an example of a positive feedback loop in hormone regulation?

Accepted Answer

Oxytocin release during childbirth, which increases uterine contractions and further oxytocin release

Question 8

A researcher discovers a new hormone that is a small, nonpolar molecule. It is found to bind to receptors inside the nucleus of target cells. Based on this information, to which class does this hormone most likely belong?

Accepted Answer

Steroid hormones

Question 9

Which of the following best explains why the same hormone can produce different effects in different target cells?

Accepted Answer

Target cells may have different receptors or signal transduction pathways for the hormone.

Question 10

A patient with a pituitary tumor has abnormally low levels of thyroid hormone. Which hormone is most likely being under-secreted as a result of the tumor?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Question 11

Which of the following is a correct description of the role of the hypothalamus in endocrine regulation?

Accepted Answer

It integrates nervous and endocrine signals and controls the pituitary gland.

Question 12

Which of the following best describes the function of melatonin in mammals?

Accepted Answer

Regulation of biological rhythms associated with reproduction and daily activity

Question 13

A person is exposed to chronic stress, resulting in prolonged activation of the adrenal cortex. Which hormone is likely to be elevated, and what is one effect of this hormone?

Accepted Answer

Cortisol; increased glucose metabolism

Question 14

Which of the following is a function of prostaglandins as local regulators?

Accepted Answer

Mediation of immune responses and blood clotting

Question 15

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

Accepted Answer

Endocrine glands are ductless and secrete hormones into the bloodstream; exocrine glands have ducts and secrete substances onto body surfaces or into cavities.

Question 16

Which hormone is released in response to low blood calcium levels, and what is one of its effects?

Accepted Answer

Parathyroid hormone (PTH); stimulates release of calcium from bones

Question 17

Which of the following is a correct example of a hormone cascade pathway?

Accepted Answer

Hypothalamus releases TRH → Anterior pituitary releases TSH → Thyroid gland releases thyroid hormone

Question 18

A mutation causes the loss of function of the gene encoding the receptor for estradiol in female frogs. Which process would be most directly affected?

Accepted Answer

Transcription of the vitellogenin gene in liver cells

Question 19

Which of the following best describes the role of mineralocorticoids such as aldosterone?

Accepted Answer

Regulation of salt and water balance in the body

Question 20

Which hormone is primarily responsible for the development of male secondary sex characteristics, and what controls its synthesis?

Accepted Answer

Testosterone; controlled by gonadotropins from the anterior pituitary

Hormones and the Endocrine System: Mechanisms and Regulation

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