Question 1

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

Accepted Answer

Water-soluble hormones require cell surface receptors and activate signal transduction pathways, while lipid-soluble hormones diffuse through the membrane and bind to cytoplasmic or nuclear receptors.

Question 2

A patient is diagnosed with hypothyroidism, resulting in a decreased metabolic rate. Which hormone is most likely deficient, and what is its primary mechanism of action?

Accepted Answer

Thyroxine; binds to intranuclear receptors to increase gene expression for metabolic enzymes.

Question 3

Which of the following is an example of a hormone that acts through a positive feedback mechanism in plants?

Accepted Answer

Ethylene during fruit ripening

Question 4

Which hormone is secreted by the pineal gland and what is its primary function?

Accepted Answer

Melatonin; regulates circadian rhythms

Question 5

A researcher applies a hormone to a plant, resulting in increased resistance to bacterial infection throughout the plant and in neighboring plants. Which hormone is most likely responsible?

Accepted Answer

Salicylic acid (SA) and its volatile form MeSA

Question 6

Which of the following best explains why only certain cells respond to a specific hormone?

Accepted Answer

Only cells with the appropriate receptor for the hormone can respond.

Question 7

Which class of hormones is most likely to act through second messenger pathways, and which is a classic example?

Accepted Answer

Amines; epinephrine

Question 8

Which gland releases growth hormone (GH), and what is one of its primary effects?

Accepted Answer

Anterior pituitary; stimulates growth of bones and tissues

Question 9

A person is exposed to a sudden stressor. Which hormones are released from the adrenal medulla, and what is their immediate effect?

Accepted Answer

Epinephrine and norepinephrine; increase heart rate and blood glucose

Question 10

Which of the following is a key difference between animal and plant hormone signaling?

Accepted Answer

Animal hormones are produced in specialized glands, while plant hormones can be produced in many tissues and often act locally.

Question 11

Which hormone is most associated with the systemic acquired resistance (SAR) response in plants, and what is its volatile form?

Accepted Answer

Salicylic acid (SA); methyl salicylate (MeSA)

Question 12

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

Accepted Answer

It is the main control center, receiving nervous input and controlling the pituitary gland.

Question 13

Which of the following is NOT a function of the thyroid gland?

Accepted Answer

Regulation of immune cell maturation

Question 14

Which hormone is produced in response to herbivore attack in plants and helps defend against them?

Accepted Answer

Jasmonic acid (JA)

Question 15

Which of the following is a correct sequence of events for a water-soluble hormone signaling pathway?

Accepted Answer

Hormone binds cell surface receptor → activates second messenger → cellular response

Question 16

Which hormone is released from the posterior pituitary and what is one of its target tissues?

Accepted Answer

Oxytocin; uterine muscles or mammary glands

Question 17

Which of the following best describes systemic acquired resistance (SAR) in plants?

Accepted Answer

A defense response at the infection site that produces signals to warn other tissues, resulting in increased defensive chemicals throughout the plant.

Question 18

Which of the following is a correct match between hormone class and example?

Accepted Answer

Polypeptides; glucagon

Question 19

Which hormone is responsible for decreasing blood calcium levels, and where is it produced?

Accepted Answer

Calcitonin; thyroid gland

Question 20

Which of the following is a function of the thymus gland?

Accepted Answer

Maturation and specialization of T cells for immune defense

Communication in Animals and Plants: Hormones – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards