Question 1

Which of the following is true during a typical cAMP- type signal transduction event?

Accepted Answer

A)  The hormone activates the second messenger by directly binding to it. 
B)  The second messenger is the last part of the system to be activated. 
C)  Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation occurs. 
D)  The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected. 
A)  The hormone activates the second messenger by directly binding to it. 
B)  The second messenger is the last part of the system to be activated. 
C)  Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation occurs. 
D)  The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected.

Question 2

Analysis of a blood sample from an individual who had fasted for 24 hours would be expected to reveal high levels of which of the following?

Accepted Answer

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

Question 3

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

Accepted Answer

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

Question 4

Which of the following is an example of negative feedback?

Accepted Answer

A)  A stressful stimulus leads to the release of epinephrine, which increases fatty acid and glucose in the blood and cardiovascular activity. 
B)  When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases. 
C)  During birthing contractions, oxytocin is released and acts to stimulate further contractions. 
D)  When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin. 
A)  A stressful stimulus leads to the release of epinephrine, which increases fatty acid and glucose in the blood and cardiovascular activity. 
B)  When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases. 
C)  During birthing contractions, oxytocin is released and acts to stimulate further contractions. 
D)  When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin.

Question 5

After drinking alcoholic beverages, increased urine excretion is the result of which of the following?

Accepted Answer

A)  increased aldosterone production 
B)  inhibited secretion of antidiuretic hormone ADH) 
C)  increased blood pressure 
D)  increased reabsorption of water in the proximal tubule 
E)  the osmoregulator cells of the brain increasing their activity 
A)  increased aldosterone production 
B)  inhibited secretion of antidiuretic hormone ADH) 
C)  increased blood pressure 
D)  increased reabsorption of water in the proximal tubule 
E)  the osmoregulator cells of the brain increasing their activity

Question 6

Which of the following is similar in structure to cholesterol?

Accepted Answer

A)  testosterone 
B)  estradiol 
C)  cortisol 
D)  all of the above 
E)  only A and B 
A)  testosterone 
B)  estradiol 
C)  cortisol 
D)  all of the above 
E)  only A and B

Question 7

The release of hormones by the posterior pituitary is the result of what process?

Accepted Answer

A)  Releasing hormones from the hypothalamus directs the production and release of oxytocin from the posterior pituitary. 
B)  Neurosecretory cells of the hypothalamus directly release hormones into blood vessels within the posterior pituitary. 
C)  The anterior pituitary regulates the activity of the posterior pituitary gland. 
D)  Hypothalamic neurons form synapses on the adrenal gland, which in turn regulates the pituitary. 
E)  The release of regulatory hormones increases activity in the adrenal medulla, altering the activity of the posterior pituitary. 
A)  Releasing hormones from the hypothalamus directs the production and release of oxytocin from the posterior pituitary. 
B)  Neurosecretory cells of the hypothalamus directly release hormones into blood vessels within the posterior pituitary. 
C)  The anterior pituitary regulates the activity of the posterior pituitary gland. 
D)  Hypothalamic neurons form synapses on the adrenal gland, which in turn regulates the pituitary. 
E)  The release of regulatory hormones increases activity in the adrenal medulla, altering the activity of the posterior pituitary.

Question 8

When partially digested food enters the small intestine from the stomach, several events must occur to protect the intestine and allow for the continued digestion of the food. One hormone in particular performs two of these functions. What intestinal hormone is responsible for causing the pancreas to release digestive enzymes and the gall bladder to release bile salts into the intestine?

Accepted Answer

A)  secretin 
B)  cholecystokinin 
C)  epinephrine 
D)  corticosterone 
E)  insulin 
A)  secretin 
B)  cholecystokinin 
C)  epinephrine 
D)  corticosterone 
E)  insulin

Question 9

Which of the following are examples of amplification of a hormone signal?
I. Epinephrine initiates an enzyme cascade.
II. Steroids bind hormone- response elements in the cell and initiate the transcription of many genes.
III. A quantity of 0.09 mg of growth hormone leads to a 10 000- mg weight gain in a cow.
IV. Different cell types have different receptors capable of binding the same hormone.

Accepted Answer

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

Question 10

Which of these glands lies closest to the throat region?

Accepted Answer

A)  hypothalamus 
B)  thyroid 
C)  pancreas 
D)  pituitary 
E)  adrenal 
A)  hypothalamus 
B)  thyroid 
C)  pancreas 
D)  pituitary 
E)  adrenal

Question 11

Which of the following statements correctly describes the relationship between the hypothalamus H) and the anterior AP) and posterior PP) lobes of the pituitary?

Accepted Answer

A)  The AP regulates the H through negative feedback mechanisms while the PP regulates the H through positive feedback. 
B)  The H is the neural system that releases hormones directly into the AP and communicates with the PP only through the circulation. 
C)  The H communicates directly with the PP and indirectly with the AP through the circulatory system. 
D)  The H regulates secretions from the PP, which then regulates all secretions from the AP. 
A)  The AP regulates the H through negative feedback mechanisms while the PP regulates the H through positive feedback. 
B)  The H is the neural system that releases hormones directly into the AP and communicates with the PP only through the circulation. 
C)  The H communicates directly with the PP and indirectly with the AP through the circulatory system. 
D)  The H regulates secretions from the PP, which then regulates all secretions from the AP.

Question 12

Polypeptides can have which of the following types of effects?

Accepted Answer

A)  autocrine 
B)  paracrine 
C)  endocrine 
D)  all of the above 
E)  only A and C 
A)  autocrine 
B)  paracrine 
C)  endocrine 
D)  all of the above 
E)  only A and C

Question 13

A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide are showing which type of cell- to- cell signalling?

Accepted Answer

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

Question 14

Predict the effects of a drug that increases adrenocorticotropic hormone ACTH) synthesis.

Accepted Answer

A)  decrease in cortisol release 
B)  decrease in release of corticotropin- releasing hormone CRH) 
C)  increase in glucocorticoid production 
D)  increase in release of corticotropin- releasing hormone CRH) 
E)  all of the above 
A)  decrease in cortisol release 
B)  decrease in release of corticotropin- releasing hormone CRH) 
C)  increase in glucocorticoid production 
D)  increase in release of corticotropin- releasing hormone CRH) 
E)  all of the above

Question 15

You have three strains of mice: A, B, and C. You experimentally manipulate each strain and find that all three show increased secretion of molecule X. Now you perform a parabiosis experiment with the three combinations of these mice: AB, AC, and BC. You perform the same experimental manipulation as above on one mouse of each pair without directly affecting the other mouse and look for effects on the other mouse. You find no detectable effect on the unmanipulated partner in any of the combinations. What is the logical conclusion based on these results?

Accepted Answer

A)  The effect on molecule X is not mediated by nerves. 
B)  The effect on molecule X is not mediated by hormones. 
C)  The effect on molecule X was just an artifact of the first experiment. 
D)  The effect on molecule X is controlled by higher integrative centers of the brain. 
A)  The effect on molecule X is not mediated by nerves. 
B)  The effect on molecule X is not mediated by hormones. 
C)  The effect on molecule X was just an artifact of the first experiment. 
D)  The effect on molecule X is controlled by higher integrative centers of the brain.

Question 16

Signal transduction occurs when a chemical message at the cell surface elicits a response inside the cell. Which one of the following events is not associated with signal transduction?

Accepted Answer

A)  second messenger activation 
B)  protein phosphorylation 
C)  internal receptor binding 
D)  cell- surface receptor binding 
A)  second messenger activation 
B)  protein phosphorylation 
C)  internal receptor binding 
D)  cell- surface receptor binding

Question 17

Coffee drinkers urinate more frequently than those who do not drink coffee or other caffeinated beverages. Which of the following is a reasonable hypothesis for the effect of caffeine on your body?

Accepted Answer

A)  Caffeine inhibits the release of erythropoietin. 
B)  Caffeine stimulates the release of erythropoietin. 
C)  Caffeine stimulates the release of antidiuretic hormone ADH). 
D)  Caffeine inhibits the release of antidiuretic hormone ADH). 
A)  Caffeine inhibits the release of erythropoietin. 
B)  Caffeine stimulates the release of erythropoietin. 
C)  Caffeine stimulates the release of antidiuretic hormone ADH). 
D)  Caffeine inhibits the release of antidiuretic hormone ADH).

Question 18

You spend two months in the mountains of Peru at ~ 3500 m altitude. After returning to Toronto, you notice that you can run your regular 10 km route significantly more easily than before you left. What is the reason for this burst of fitness?

Accepted Answer

A)  The time you spent at a high altitude resulted in an increased lung capacity and therefore extra oxygen intake. This extra oxygen stimulated the release of EP and in turn the production of red blood cells. 
B)  Due to lower oxygen concentrations at high altitudes, low blood oxygen levels stimulated release of EPO, which stimulated the production of red blood cells. This increased the oxygen binding capacity of your blood. 
C)  You were in the mountains, so you must have been hiking every day and got in better shape. 
D)  The time spent at a high altitude resulted in an increased active metabolic rate and therefore increased ATP production. 
A)  The time you spent at a high altitude resulted in an increased lung capacity and therefore extra oxygen intake. This extra oxygen stimulated the release of EP and in turn the production of red blood cells. 
B)  Due to lower oxygen concentrations at high altitudes, low blood oxygen levels stimulated release of EPO, which stimulated the production of red blood cells. This increased the oxygen binding capacity of your blood. 
C)  You were in the mountains, so you must have been hiking every day and got in better shape. 
D)  The time spent at a high altitude resulted in an increased active metabolic rate and therefore increased ATP production.

Exam 46: Chemical Signals in Animals

Which of the following is true during a typical cAMP- type signal transduction event?

Analysis of a blood sample from an individual who had fasted for 24 hours would be expected to reveal high levels of which of the following?

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

Which of the following is an example of negative feedback?

After drinking alcoholic beverages, increased urine excretion is the result of which of the following?

Which of the following is similar in structure to cholesterol?

The release of hormones by the posterior pituitary is the result of what process?

Which of these glands lies closest to the throat region?

Which of the following statements correctly describes the relationship between the hypothalamus H) and the anterior AP) and posterior PP) lobes of the pituitary?

Polypeptides can have which of the following types of effects?

A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide are showing which type of cell- to- cell signalling?

Predict the effects of a drug that increases adrenocorticotropic hormone ACTH) synthesis.

Signal transduction occurs when a chemical message at the cell surface elicits a response inside the cell. Which one of the following events is not associated with signal transduction?

Coffee drinkers urinate more frequently than those who do not drink coffee or other caffeinated beverages. Which of the following is a reasonable hypothesis for the effect of caffeine on your body?

You spend two months in the mountains of Peru at ~ 3500 m altitude. After returning to Toronto, you notice that you can run your regular 10 km route significantly more easily than before you left. What is the reason for this burst of fitness?

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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