Question 1

A paracrine signal that relaxes smooth muscle cells is

Accepted Answer

A) nitric oxide. 
B) vitamin D. 
C) testosterone. 
D) cortisol. 
E) antidiuretic hormone. 
A) nitric oxide. 
B) vitamin D. 
C) testosterone. 
D) cortisol. 
E) antidiuretic hormone.

Question 2

Tadpoles must undergo a major metamorphosis to become frogs.This change includes reabsorption of the tail,growth of limbs,calcification of the skeleton,increase in rhodopsin in the eye,development of lungs,change in hemoglobin structure,and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore.Amazingly,all of these changes are induced by thyroxine.What is the most likely explanation for such a wide array of effects of thyroxine?

Accepted Answer

A) There are many different forms of thyroxine, each specific to a different tissue. 
B) Different tissues have thyroxine receptors that activate different signal transduction pathways. 
C) Some tissues have membrane receptors for thyroxine, while other tissues have thyroxine receptors within the nucleus. 
D) Different releasing hormones release thyroxine to different tissues. 
E) Thyroxine can be broken down by the tadpole into several signalling molecules. 
A) There are many different forms of thyroxine, each specific to a different tissue. 
B) Different tissues have thyroxine receptors that activate different signal transduction pathways. 
C) Some tissues have membrane receptors for thyroxine, while other tissues have thyroxine receptors within the nucleus. 
D) Different releasing hormones release thyroxine to different tissues. 
E) Thyroxine can be broken down by the tadpole into several signalling molecules.

Question 3

Glucocorticoids do which of the following?

Accepted Answer

A) promote the immune response 
B) promote the release of fatty acids 
C) increase blood glucose levels 
D) increase insulin production 
E) promote reabsorption of sodium 
A) promote the immune response 
B) promote the release of fatty acids 
C) increase blood glucose levels 
D) increase insulin production 
E) promote reabsorption of sodium

Question 4

If a biochemist discovers a new molecule,which of the following pieces of data would allow her to draw the conclusion that the molecule is a steroid hormone?
I.The molecule is lipid soluble.
II.The molecule is derived from a series of steps beginning with cholesterol.
III.The molecule acts at a target tissue some distance from where it is produced.
IV.The molecule uses a carrier protein when in an aqueous solution such as blood.

Accepted Answer

A) only I and III 
B) only II and IV 
C) only I, II and III 
D) only I, III, and IV 
E) I, II, III, and IV 
A) only I and III 
B) only II and IV 
C) only I, II and III 
D) only I, III, and IV 
E) I, II, III, and IV

Question 5

Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?

Accepted Answer

A) greater production of T₃ than of T₄ 
B) hyposecretion of TSH 
C) hypersecretion of TSH 
D) hypersecretion of MSH 
E) a decrease in the thyroid secretion of calcitonin 
A) greater production of T₃ than of T₄ 
B) hyposecretion of TSH 
C) hypersecretion of TSH 
D) hypersecretion of MSH 
E) a decrease in the thyroid secretion of calcitonin

Question 6

A product of the anterior pituitary gland that causes colour changes in its target cells is

Accepted Answer

A) FSH. 
B) LH. 
C) TSH. 
D) MSH. 
E) ACTH. 
A) FSH. 
B) LH. 
C) TSH. 
D) MSH. 
E) ACTH.

Question 7

Hormones that promote homeostasis

Accepted Answer

A) are not found as members of antagonistic signalling mechanisms. 
B) travel to target cells without passage in the plasma. 
C) utilize receptors that bind any hormone. 
D) initiate signal transduction in the target cell without binding to receptors. 
E) usually operate as part of a negative feedback system. 
A) are not found as members of antagonistic signalling mechanisms. 
B) travel to target cells without passage in the plasma. 
C) utilize receptors that bind any hormone. 
D) initiate signal transduction in the target cell without binding to receptors. 
E) usually operate as part of a negative feedback system.

Question 8

In an experiment,rats' ovaries were removed immediately after impregnation and then the rats were divided into two groups.Treatments and results are summarized in the table.The results most likely occurred because progesterone exerts an effect on the

Accepted Answer

A) general health of the rat. 
B) size of the fetus. 
C) metabolism of the uterus. 
D) gestation period of rats. 
E) number of eggs fertilized. 
A) general health of the rat. 
B) size of the fetus. 
C) metabolism of the uterus. 
D) gestation period of rats. 
E) number of eggs fertilized.

Question 9

A chemical signal operating in a paracrine manner is one that

Accepted Answer

A) is active at a neuronal synapse. 
B) affects only the cells that synthesize the paracrine signal. 
C) requires transport in the blood before it can act on its target cells. 
D) evokes responses from all parts of the vascular system. 
E) must move through the air before it reaches its target cells. 
A) is active at a neuronal synapse. 
B) affects only the cells that synthesize the paracrine signal. 
C) requires transport in the blood before it can act on its target cells. 
D) evokes responses from all parts of the vascular system. 
E) must move through the air before it reaches its target cells.

Question 10

Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of

Accepted Answer

A) insulin. 
B) glucagon. 
C) secretin. 
D) gastrin. 
E) glucose. 
A) insulin. 
B) glucagon. 
C) secretin. 
D) gastrin. 
E) glucose.

Question 11

A tropic hormone from the anterior pituitary gland regulates the secretion of

Accepted Answer

A) parathyroid hormone. 
B) calcitonin. 
C) epinephrine. 
D) thyroxine. 
E) glucagon. 
A) parathyroid hormone. 
B) calcitonin. 
C) epinephrine. 
D) thyroxine. 
E) glucagon.

Question 12

Testosterone is an example of

Accepted Answer

A) an androgen. 
B) an estrogen. 
C) a progestin. 
D) a catecholamine. 
E) an adrenal steroid. 
A) an androgen. 
B) an estrogen. 
C) a progestin. 
D) a catecholamine. 
E) an adrenal steroid.

Question 13

In a positive-feedback system in which hormone A alters the amount of protein X

Accepted Answer

A) an increase in A always produces an increase in X. 
B) an increase in X always produces a decrease in A. 
C) a decrease in A always produces an increase in X. 
D) a decrease in X always causes a decrease in A. 
E) it is impossible to predict how A and X affect each other. 
A) an increase in A always produces an increase in X. 
B) an increase in X always produces a decrease in A. 
C) a decrease in A always produces an increase in X. 
D) a decrease in X always causes a decrease in A. 
E) it is impossible to predict how A and X affect each other.

Question 14

Osteoporosis is a condition characterized by weak bones resulting from calcium loss.The hormone responsible for blood calcium regulation is

Accepted Answer

A) LH. 
B) HGH. 
C) PTH. 
D) ACTH. 
E) FSH. 
A) LH. 
B) HGH. 
C) PTH. 
D) ACTH. 
E) FSH.

Question 15

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that

Accepted Answer

A) only its target cells get exposed to aldosterone. 
B) only its target cells contain aldosterone receptors. 
C) it is unable to enter nontarget cells. 
D) nontarget cells destroy aldosterone before it can produce any effect. 
E) nontarget cells convert aldosterone to a hormone to which they do respond. 
A) only its target cells get exposed to aldosterone. 
B) only its target cells contain aldosterone receptors. 
C) it is unable to enter nontarget cells. 
D) nontarget cells destroy aldosterone before it can produce any effect. 
E) nontarget cells convert aldosterone to a hormone to which they do respond.

Question 16

Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins?

Accepted Answer

A) neurohormones 
B) estrogens 
C) androgens 
D) vitamin D 
E) neurohormones, estrogens, androgens, and vitamin D 
A) neurohormones 
B) estrogens 
C) androgens 
D) vitamin D 
E) neurohormones, estrogens, androgens, and vitamin D

Question 17

Removing which of the following glands would have the most wide-reaching effect on bodily functions of an adult human?

Accepted Answer

A) adrenal glands 
B) pituitary gland 
C) thyroid gland 
D) ovaries (in female)or testes (in male) 
E) pineal gland 
A) adrenal glands 
B) pituitary gland 
C) thyroid gland 
D) ovaries (in female)or testes (in male) 
E) pineal gland

Question 18

Nitric oxide and norepinephrine

Accepted Answer

A) both function as neurotransmitters. 
B) both function as steroid hormones. 
C) are both involved in the "fight-or-flight" response. 
D) bind the same receptors. 
E) both cause a reduction in the blood levels of glucose. 
A) both function as neurotransmitters. 
B) both function as steroid hormones. 
C) are both involved in the "fight-or-flight" response. 
D) bind the same receptors. 
E) both cause a reduction in the blood levels of glucose.

Question 19

Based on their effects,which pair below would not be expected to be active at the same time and place?

Accepted Answer

A) prostaglandin and nitric oxide 
B) growth hormone and insulin-like growth factors 
C) endocrine and exocrine glands 
D) hormones and target cells 
E) neurosecretory cells and neurotransmitters 
A) prostaglandin and nitric oxide 
B) growth hormone and insulin-like growth factors 
C) endocrine and exocrine glands 
D) hormones and target cells 
E) neurosecretory cells and neurotransmitters

Question 20

Portal blood vessels connect two capillary beds found in the

Accepted Answer

A) hypothalamus and thalamus. 
B) anterior pituitary and posterior pituitary. 
C) hypothalamus and anterior pituitary. 
D) posterior pituitary and thyroid gland. 
E) anterior pituitary and adrenal gland. 
A) hypothalamus and thalamus. 
B) anterior pituitary and posterior pituitary. 
C) hypothalamus and anterior pituitary. 
D) posterior pituitary and thyroid gland. 
E) anterior pituitary and adrenal gland.

Exam 45: Hormones and the Endocrine System

A paracrine signal that relaxes smooth muscle cells is

Glucocorticoids do which of the following?

Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?

A product of the anterior pituitary gland that causes colour changes in its target cells is

Hormones that promote homeostasis

In an experiment,rats' ovaries were removed immediately after impregnation and then the rats were divided into two groups.Treatments and results are summarized in the table.The results most likely occurred because progesterone exerts an effect on the

A chemical signal operating in a paracrine manner is one that

Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of

A tropic hormone from the anterior pituitary gland regulates the secretion of

Testosterone is an example of

In a positive-feedback system in which hormone A alters the amount of protein X

Osteoporosis is a condition characterized by weak bones resulting from calcium loss.The hormone responsible for blood calcium regulation is

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that

Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins?

Removing which of the following glands would have the most wide-reaching effect on bodily functions of an adult human?

Nitric oxide and norepinephrine

Based on their effects,which pair below would not be expected to be active at the same time and place?

Portal blood vessels connect two capillary beds found in the

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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