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| 1 | |
When comparing the endocrine system and the nervous system, generally speaking, the endocrine system |
| | A) | is faster-acting than the nervous system. |
| | B) | produces effects that are of shorter duration. |
| | C) | uses amplitude-modulated signals. |
| | D) | produces more localized effects. |
| | E) | relies less on chemical signals. |
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| 2 | |
A chemical signal released from a cell that has a local effect on the same cell type from which the chemical signal is released is a(n) |
| | A) | paracrine chemical signal. |
| | B) | pheromone. |
| | C) | autocrine chemical signal. |
| | D) | hormone. |
| | E) | intracellular mediator. |
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| 3 | |
Given this list of molecule types:
1. nucleic acid derivatives
2. fatty acid derivatives
3. polypeptides
4. proteins
5. phospholipids
Which could be hormone molecules? |
| | A) | 1,2,3 |
| | B) | 2,3,4 |
| | C) | 1,2,3,4 |
| | D) | 2,3,4,5 |
| | E) | 1,2,3,4,5 |
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| 4 | |
Which of these regulates secretion of a hormone from an endocrine tissue? |
| | A) | other hormones |
| | B) | negative-feedback mechanisms |
| | C) | nonhormone substance in the blood |
| | D) | the nervous system |
| | E) | all of the above |
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| 5 | |
Hormones are released into the blood |
| | A) | at relatively constant levels. |
| | B) | in large amounts in response to a stimulus. |
| | C) | increasing and decreasing in a cyclic fashion. |
| | D) | all of the above. |
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| 6 | |
Lipid-soluble hormones readily diffuse through capillary walls, whereas water-soluble hormones, such as proteins, must |
| | A) | pass through capillary cells. |
| | B) | pass through pores in the capillary endothelium. |
| | C) | be moved out of the capillary by active transport. |
| | D) | remain in the blood. |
| | E) | be broken down to amino acids before leaving the blood. |
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| 7 | |
Concerning the half-life of hormones, |
| | A) | lipid-soluble hormones generally have a longer half-life. |
| | B) | hormones with shorter half-lives regulate activities with a slow onset and long duration. |
| | C) | hormones with a shorter half-life are maintained at more constant levels in the blood. |
| | D) | lipid-soluble hormones are degraded rapidly by enzymes in the circulatory system. |
| | E) | water-soluble hormones usually combine with plasma proteins. |
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| 8 | |
Given these observations:
1. A hormone will affect only a specific tissue (not all tissues).
2. A tissue can respond to more than one hormone.
3. Some tissues respond rapidly to a hormone, whereas others take many hours to respond.
Which of these observations can be explained by the characteristics of hormone receptors? |
| | A) | 1 |
| | B) | 1,2 |
| | C) | 2,3 |
| | D) | 1,3 |
| | E) | 1,2,3 |
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| 9 | |
Which of these is not a means by which hormones are eliminated from the circulatory system? |
| | A) | excreted into urine or bile |
| | B) | bound to plasma proteins |
| | C) | metabolism (enzymatically degraded in the blood) |
| | D) | actively transported into cells |
| | E) | conjugated with sulfate or glucuronic acid |
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| 10 | |
Down-regulation |
| | A) | produces a decrease in the number of receptors in the target cells. |
| | B) | produces an increase in the sensitivity of the target cells to a hormone. |
| | C) | is found in target cells that respond to hormones that are maintained at constant levels. |
| | D) | occurs partly because of an increase in receptor synthesis by the target cell. |
| | E) | all of the above. |
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| 11 | |
A chemical signal |
| | A) | can function as an enzyme. |
| | B) | is also a G protein. |
| | C) | can bind to a receptor site. |
| | D) | is an intracellular mediator. |
| | E) | all of the above. |
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| 12 | |
Activated G proteins can |
| | A) | cause ion channels to open or close. |
| | B) | activate adenylate cyclase. |
| | C) | inhibit the synthesis of cAMP. |
| | D) | alter the activity of IP3. |
| | E) | all of the above. |
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| 13 | |
Given these events:
1. GTP is converted to GDP.
2. The a subunit separates from b the and g units.
3. GDP is released from the a subunit.
List the order in which the events occur after a chemical signal binds to a membrane-bound receptor. |
| | A) | 1,2,3 |
| | B) | 1,3,2 |
| | C) | 2,3,1 |
| | D) | 3,2,1 |
| | E) | 3,1,2 |
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| 14 | |
Which of these can limit the response of a cell to a chemical signal? |
| | A) | phosphodiesterase |
| | B) | converting GTP to GDP |
| | C) | decreasing the number of receptors |
| | D) | blocking binding sites |
| | E) | all of the above |
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| 15 | |
Given these events:
1. Na+ channels open.
2. Na+ channels close.
3. The plasma membrane depolarizes.
4. The plasma membrane hyperpolarizes.
Choose the arrangement that lists the events in the order they occur after serotonin binds to its receptor. |
| | A) | 1,3 |
| | B) | 1,4 |
| | C) | 2,3 |
| | D) | 2,4 |
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| 16 | |
Given these events:
1. The a subunit of a G protein interacts with Ca2+ channels.
2. Ca2+ diffuse into the cell.
3. The a subunit of a G protein is activated.
Choose the arrangement that lists the events in the order they occur after a chemical signal combines with a receptor on a smooth muscle cell. |
| | A) | 1,2,3 |
| | B) | 1,3,2 |
| | C) | 2,1,3 |
| | D) | 3,1,2 |
| | E) | 3,2,1 |
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| 17 | |
Given these events:
1. cAMP is synthesized.
2. The a subunit of G protein is activated.
3. Phosphodiesterase breaks down cAMP.
Choose the arrangement that lists the events in the order they occur after a chemical signal binds to a receptor. |
| | A) | 1,2,3 |
| | B) | 1,3,2 |
| | C) | 2,1,3 |
| | D) | 2,3,1 |
| | E) | 3,2,1 |
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| 18 | |
Which of these events can occur after a G protein activates phospholipase C? |
| | A) | DAG and IP3 are synthesized from PIP2. |
| | B) | IP3 causes Ca2+ channels to open. |
| | C) | DAG activates enzymes that synthesize prostaglandins. |
| | D) | All of the above. |
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| 19 | |
When a chemical signal binds to an intracellular receptor |
| | A) | DNA produces mRNA. |
| | B) | G proteins are activated. |
| | C) | the receptor-hormone complex causes ion channels to open or close. |
| | D) | the cell's response is faster than when a chemical signal binds to a membrane-bound receptor. |
| | E) | the chemical signal is usually a large, water-soluble molecule. |
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| 20 | |
Given these events:
1. activation of cAMP
2. activation of genes
3. enzyme activity altered
Which of these events can occur when a hormone binds to an intracellular hormone receptor? |
| | A) | 1 |
| | B) | 1,2 |
| | C) | 2,3 |
| | D) | 1,2,3 |
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