Question 1

Oxytocin helps initiate labour in mammals. During labour and delivery, the contraction of uterine muscles increases the release of oxytocin. This is an example of

Accepted Answer

A)  a hormone that is involved in a positive feedback loop. 
B)  signal transduction immediately changing gene expression in its target cells. 
C)  a negative feedback system. 
D)  the key role of the anterior pituitary gland in regulating uterine contraction. 
E)  a hormone that acts in an antagonistic way with another hormone. 
A)  a hormone that is involved in a positive feedback loop. 
B)  signal transduction immediately changing gene expression in its target cells. 
C)  a negative feedback system. 
D)  the key role of the anterior pituitary gland in regulating uterine contraction. 
E)  a hormone that acts in an antagonistic way with another hormone. A

Question 2

Of the following types of molecules, which can function as both neurotransmitters and hormones?

Accepted Answer

A)  second messengers 
B)  catecholamines 
C)  adipocytes 
D)  glucocorticoids 
A)  second messengers 
B)  catecholamines 
C)  adipocytes 
D)  glucocorticoids B

Question 3

Which of the following statements is not true of hormones?

Accepted Answer

A)  Some have only local effects on nearby cells. 
B)  Some are derived from amino acids. 
C)  All are organic molecules. 
D)  All are secreted from the cells where they are synthesized. 
E)  They have large effects on target tissues relative to their concentrations. 
A)  Some have only local effects on nearby cells. 
B)  Some are derived from amino acids. 
C)  All are organic molecules. 
D)  All are secreted from the cells where they are synthesized. 
E)  They have large effects on target tissues relative to their concentrations. A

Question 4

In human embryonic development, which of the following pairs of hormones are released by the developing testes and result in development of the male reproductive tract and inhibition of the female reproductive tract?

Accepted Answer

A)  estrogen and progesterone 
B)  testosterone and Mullerian inhibitory substance 
C)  testosterone and estradiol 
D)  testosterone and estrogen 
E)  estradiol and estrogen 
A)  estrogen and progesterone 
B)  testosterone and Mullerian inhibitory substance 
C)  testosterone and estradiol 
D)  testosterone and estrogen 
E)  estradiol and estrogen

Question 5

What changes might you predict/expect if a mutation caused a change in the timing of juvenile hormone, such that it remained high throughout the lifetime of the organism?

Accepted Answer

A)  The organism would form structures that allowed it to respond to stress. 
B)  The organism would mature reproductively. 
C)  The organism would undergo metamorphosis at an earlier time. 
D)  The organism would maintain its juvenile state for the remainder of its life. 
A)  The organism would form structures that allowed it to respond to stress. 
B)  The organism would mature reproductively. 
C)  The organism would undergo metamorphosis at an earlier time. 
D)  The organism would maintain its juvenile state for the remainder of its life.

Question 6

In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons?

Accepted Answer

A)  To numb the organ so that it can be probed without inducing pain in the lab animal. 
B)  To impair the normal functions of the organ so that the hormonal effect can be more easily studied. 
C)  To make sure that the effect is not occurring through actions in the nervous system. 
D)  To make sure that the organ being effected cannot function unless the researchers stimulate it with an external electrical probe. 
A)  To numb the organ so that it can be probed without inducing pain in the lab animal. 
B)  To impair the normal functions of the organ so that the hormonal effect can be more easily studied. 
C)  To make sure that the effect is not occurring through actions in the nervous system. 
D)  To make sure that the organ being effected cannot function unless the researchers stimulate it with an external electrical probe.

Question 7

What do steroid and peptide hormones typically have in common?

Accepted Answer

A)  their requirement for travel through the bloodstream 
B)  the building blocks from which they are synthesized 
C)  their solubility in cell membranes 
D)  the location of their receptors 
E)  their reliance on signal transduction in the cell 
A)  their requirement for travel through the bloodstream 
B)  the building blocks from which they are synthesized 
C)  their solubility in cell membranes 
D)  the location of their receptors 
E)  their reliance on signal transduction in the cell

Question 8

How can the body prevent a hormone with different effects on different tissues from acting on inappropriate cells at inappropriate times?

Accepted Answer

A)  Internalize receptors on nontargeted cells. 
B)  Shunt blood supply to the desired tissues. 
C)  Change the conformation of receptors on nontargeted cells. 
D)  All of the above answers apply. 
A)  Internalize receptors on nontargeted cells. 
B)  Shunt blood supply to the desired tissues. 
C)  Change the conformation of receptors on nontargeted cells. 
D)  All of the above answers apply.

Question 9

People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin properly. Relative to normal individuals, what would be the effect on blood glucose levels of chronic stress that kept blood cortisol levels high?

Accepted Answer

A)  There would be about the same effect on blood glucose levels in both types of individuals. 
B)  There would be less increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
C)  There would be less decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
D)  There would be a greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
E)  There would be a greater decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
A)  There would be about the same effect on blood glucose levels in both types of individuals. 
B)  There would be less increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
C)  There would be less decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
D)  There would be a greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals. 
E)  There would be a greater decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

Question 10

The regulation of blood sugar levels and our stress responses are controlled in part by a negative feedback loop involving cortisol, ACTH, and CRH. What would likely be the result during times of stress if cortisol receptors in the hypothalamus were nonfunctional?

Accepted Answer

A)  Blood sugar levels would be unaffected. 
B)  Cortisol production would cease. 
C)  CRH production would cease. 
D)  Blood sugar levels would rise to dangerous levels. 
E)  ACTH production would cease. 
A)  Blood sugar levels would be unaffected. 
B)  Cortisol production would cease. 
C)  CRH production would cease. 
D)  Blood sugar levels would rise to dangerous levels. 
E)  ACTH production would cease.

Question 11

You are dissecting a fish in your biology laboratory section. Your teaching assistant points out a long oval structure and tells you it is an endocrine gland. Which of the following is true about this structure?

Accepted Answer

A)  It secretes a product that is carried in the bloodstream or other fluids to target cells. 
B)  The gland's product will interact with receptors on the cell membrane or inside target cells. 
C)  The gland's product is secreted into the cavity of some organ, outside of the circulatory system. 
D)  Only answers A and B apply. 
E)  Only answers B and C apply. 
A)  It secretes a product that is carried in the bloodstream or other fluids to target cells. 
B)  The gland's product will interact with receptors on the cell membrane or inside target cells. 
C)  The gland's product is secreted into the cavity of some organ, outside of the circulatory system. 
D)  Only answers A and B apply. 
E)  Only answers B and C apply.

Question 12

How can a single hormone can have multiple effects?

Accepted Answer

A)  There could be different types of receptors in different target tissues. 
B)  There could be different second messengers in different target tissues. 
C)  There could be different signaling cascades in different target tissues. 
D)  All of the above answers apply. 
E)  Only answers A and B apply. 
A)  There could be different types of receptors in different target tissues. 
B)  There could be different second messengers in different target tissues. 
C)  There could be different signaling cascades in different target tissues. 
D)  All of the above answers apply. 
E)  Only answers A and B apply.

Question 13

Which of the following best describes the neuroendocrine- to- endocrine pathway of hormone action?

Accepted Answer

A)  a gland that releases hormones directly into a neural structure, thus regulating neural functions 
B)  a gland that exhibits negative feedback on the nervous system by releasing hormones into neural tissue both directly and indirectly through the circulation 
C)  a neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the effected gland 
D)  a neural organ that produces hormones releases its hormones directly into another gland that it regulates 
A)  a gland that releases hormones directly into a neural structure, thus regulating neural functions 
B)  a gland that exhibits negative feedback on the nervous system by releasing hormones into neural tissue both directly and indirectly through the circulation 
C)  a neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the effected gland 
D)  a neural organ that produces hormones releases its hormones directly into another gland that it regulates

Question 14

Which of the following is not considered a second messenger?

Accepted Answer

A)  norepinephrine 
B)  IP3 
C)  cAMP 
D)  DAG 
A)  norepinephrine 
B)  IP3 
C)  cAMP 
D)  DAG

Question 15

A weightlifter decides to try taking steroids to improve his performance level. Following a month of use, he notes that the steroids have had no effect on his performance. Which of the following is the most likely reason for this?

Accepted Answer

A)  The steroid hormone did not enter the nucleus and could not bind to the hormone response element. 
B)  The steroid hormone did not bind to the receptors at the cell surface and no signal transduction cascade was initiated. 
C)  The steroid hormone did no bind to the hormone receptor and the hormone response element was not activated. 
D)  The protein needed to transport the steroid hormone into the cell was not present at the cell membrane. 
A)  The steroid hormone did not enter the nucleus and could not bind to the hormone response element. 
B)  The steroid hormone did not bind to the receptors at the cell surface and no signal transduction cascade was initiated. 
C)  The steroid hormone did no bind to the hormone receptor and the hormone response element was not activated. 
D)  The protein needed to transport the steroid hormone into the cell was not present at the cell membrane.

Question 16

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 different types of receptors. 
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)  Answers B and C both apply. 
A)  There are many different forms of thyroxine, each specific to a different tissue. 
B)  Different tissues have different types of receptors. 
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)  Answers B and C both apply.

Question 17

What property of steroid hormones allows them to cross the phospholipid bilayer?

Accepted Answer

A)  Steroid hormone transporters exist in most cell types. 
B)  Steroid hormones act on cells close to where they were produced, and very few molecules are required to travel such a short distance to cross the lipid bilayer. 
C)  Steroid hormones act on the same cells in which they are produced and, therefore, are within the cell they are acting upon. 
D)  Steroid hormones can act in very small concentrations, and very few molecules of steroids need to cross the lipid bilayer. 
E)  Steroid hormones are lipid soluble and easily cross the phospholipid bilayer. 
A)  Steroid hormone transporters exist in most cell types. 
B)  Steroid hormones act on cells close to where they were produced, and very few molecules are required to travel such a short distance to cross the lipid bilayer. 
C)  Steroid hormones act on the same cells in which they are produced and, therefore, are within the cell they are acting upon. 
D)  Steroid hormones can act in very small concentrations, and very few molecules of steroids need to cross the lipid bilayer. 
E)  Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.

Question 18

If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signalling is occurring?

Accepted Answer

A)  autocrine 
B)  endocrine 
C)  paracrine 
D)  neuroendocrine 
A)  autocrine 
B)  endocrine 
C)  paracrine 
D)  neuroendocrine

Question 19

The posterior pituitary is anatomically and developmentally an extension of the hypothalamus. Which of the following is a true statement about the posterior pituitary?

Accepted Answer

A)  The posterior pituitary's many hormone products and their diverse functions have led to it being called by the term master gland. 
B)  The posterior pituitary's hormones are actually produced in neurosecretory cells that originate in the hypothalamus. 
C)  None of the above answers apply. 
D)  Both answers A and B apply. 
A)  The posterior pituitary's many hormone products and their diverse functions have led to it being called by the term master gland. 
B)  The posterior pituitary's hormones are actually produced in neurosecretory cells that originate in the hypothalamus. 
C)  None of the above answers apply. 
D)  Both answers A and B apply.

Question 20

All of the following are examples of amplification of a hormone signal EXCEPT

Accepted Answer

A)  different cell types have different receptors capable of binding the same hormone. 
B)  0.09 mg of growth hormone leads to a 10,000- mg weight gain in a cow. 
C)  epinephrine initiates an enzyme cascade. 
D)  steroids bind hormone- response elements in the cell and initiate gene transcription. 
A)  different cell types have different receptors capable of binding the same hormone. 
B)  0.09 mg of growth hormone leads to a 10,000- mg weight gain in a cow. 
C)  epinephrine initiates an enzyme cascade. 
D)  steroids bind hormone- response elements in the cell and initiate gene transcription.

Exam 46: Chemical Signals in Animals

Oxytocin helps initiate labour in mammals. During labour and delivery, the contraction of uterine muscles increases the release of oxytocin. This is an example of

Of the following types of molecules, which can function as both neurotransmitters and hormones?

Which of the following statements is not true of hormones?

In human embryonic development, which of the following pairs of hormones are released by the developing testes and result in development of the male reproductive tract and inhibition of the female reproductive tract?

What changes might you predict/expect if a mutation caused a change in the timing of juvenile hormone, such that it remained high throughout the lifetime of the organism?

In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons?

What do steroid and peptide hormones typically have in common?

How can the body prevent a hormone with different effects on different tissues from acting on inappropriate cells at inappropriate times?

People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin properly. Relative to normal individuals, what would be the effect on blood glucose levels of chronic stress that kept blood cortisol levels high?

The regulation of blood sugar levels and our stress responses are controlled in part by a negative feedback loop involving cortisol, ACTH, and CRH. What would likely be the result during times of stress if cortisol receptors in the hypothalamus were nonfunctional?

You are dissecting a fish in your biology laboratory section. Your teaching assistant points out a long oval structure and tells you it is an endocrine gland. Which of the following is true about this structure?

How can a single hormone can have multiple effects?

Which of the following best describes the neuroendocrine- to- endocrine pathway of hormone action?

Which of the following is not considered a second messenger?

A weightlifter decides to try taking steroids to improve his performance level. Following a month of use, he notes that the steroids have had no effect on his performance. Which of the following is the most likely reason for this?

What property of steroid hormones allows them to cross the phospholipid bilayer?

If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signalling is occurring?

The posterior pituitary is anatomically and developmentally an extension of the hypothalamus. Which of the following is a true statement about the posterior pituitary?

All of the following are examples of amplification of a hormone signal EXCEPT

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Gene Structure and Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems and Global Ecology

Biodiversity and Conservation Biology

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