Question 1

Which of the following best explains a key difference between how the endocrine and nervous systems transmit signals over long distances in the body?

Accepted Answer

The endocrine system releases hormones into the bloodstream for widespread effects, while the nervous system transmits electrical signals along neurons for rapid, targeted responses.

Question 2

A plant shoot is growing towards a light source. If you cover the tip of the shoot with an opaque cap, what is the most likely effect on auxin signaling and plant growth direction?

Accepted Answer

The shoot will not bend toward the light because the opaque cap prevents light detection at the tip, disrupting auxin redistribution.

Question 3

Which of the following is a similarity between auxin signaling in plants and hormone signaling in animals?

Accepted Answer

Both involve chemical messengers that can trigger different responses in different target cells.

Question 4

A hormone is found to be lipid-soluble. Which of the following best describes how it is transported in the blood and where it acts in its target cell?

Accepted Answer

It requires a transport protein in the blood and typically binds to intracellular receptors.

Question 5

Which of the following explains how two different target cells can respond differently to the same hormone?

Accepted Answer

Each cell expresses different hormone receptors or has different signal transduction pathways.

Question 6

Which of the following best describes the relationship between the hypothalamus and the pituitary gland in hormone release?

Accepted Answer

The hypothalamus releases hormones that either stimulate or inhibit the anterior pituitary, and sends nerve signals to the posterior pituitary to release hormones.

Question 7

A patient has a diet severely lacking in iodine. Predict the likely effects on thyroid hormone levels, TSH levels, thyroid size, and basal metabolic rate.

Accepted Answer

Thyroid hormone levels decrease, TSH increases, thyroid enlarges (goiter), and metabolic rate decreases.

Question 8

Which hormone is released from the anterior pituitary in response to TRH from the hypothalamus, and what is its primary target?

Accepted Answer

TSH; thyroid gland

Question 9

A child with congenital hypothyroidism (low thyroid hormone from birth) is not treated. What is a likely long-term consequence?

Accepted Answer

Impaired intellectual development and stunted growth.

Question 10

During a stressful event, the hypothalamus releases CRH, which stimulates the anterior pituitary to release ACTH. What is the next step in this hormonal cascade?

Accepted Answer

ACTH stimulates the adrenal cortex to release cortisol.

Question 11

Which of the following best describes the action of cortisol during stress?

Accepted Answer

Cortisol increases blood glucose by stimulating gluconeogenesis in the liver.

Question 12

Which of the following is a correct sequence of hormone release in the hypothalamic-pituitary-thyroid axis?

Accepted Answer

TRH → TSH → Thyroid hormone

Question 13

A patient has a tumor in the anterior pituitary that secretes excess ACTH. Predict the likely effects on cortisol levels and the adrenal cortex.

Accepted Answer

Cortisol levels increase; adrenal cortex enlarges.

Question 14

Which of the following best describes a steroid hormone?

Accepted Answer

It is derived from cholesterol, is lipid-soluble, and binds to intracellular receptors.

Question 15

Which of the following equations best represents the negative feedback regulation of thyroid hormone production?

Accepted Answer

$$	ext{Increased thyroid hormone} ightarrow 	ext{Decreased TRH and TSH secretion}$$

Question 16

Which of the following is a water-soluble hormone and how does it typically signal in target cells?

Accepted Answer

TSH; binds to cell surface receptors and activates a signal transduction pathway.

Question 17

If a mutation causes the glucocorticoid receptor to be nonfunctional, what is the most likely effect during stress?

Accepted Answer

Cortisol will be produced, but target cells will not respond, leading to impaired stress adaptation.

Question 18

Which of the following best describes the role of the adrenal cortex in the endocrine system?

Accepted Answer

It produces steroid hormones such as cortisol in response to ACTH.

Question 19

A patient has low TRH, low TSH, and low thyroid hormone levels. Which gland is most likely malfunctioning?

Accepted Answer

Hypothalamus

Question 20

Which of the following best explains why goiter (enlarged thyroid) can develop in someone with iodine deficiency?

Accepted Answer

Low iodine prevents thyroid hormone synthesis, leading to increased TSH stimulation and thyroid growth.

The Endocrine System: Hormonal Regulation in Animals and Plants

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