Question 1

If suprachiasmatic nucleus (SCN)tissue is transplanted from a short-period hamster into a normal hamster,​ 
A)no change can be observed. 
B)the normal hamster will show 20-hour cycles. 
C)the normal hamster will show 24-hour cycles. 
D)the normal hamster will show 25-hour cycles.

Accepted Answer

The suprachiasmatic nucleus (SCN) is the primary circadian pacemaker in mammals. Transplanting SCN tissue from a short-period hamster into a normal hamster will cause the recipient to adopt the donor's circadian rhythm, resulting in 20-hour cycles.

Question 2

Courtney believes that pulling regular "all-nighters" is an important part of being a college student and she frequently goes all night without any sleep at all.Given what you know about sleep cycles and sleep deprivation,what else can you assume about Courtney? 
A)She probably is just one of those people who doesn't need much sleep. 
B)She is a conscientious student who probably has a very high grade point average 
C)She probably has a lower grade point average than most of her classmates and often feels depressed. 
D)She has probably maintained this same pattern of sleeping since childhood.

Accepted Answer

Pulling regular all-nighters can lead to sleep deprivation, which can have negative effects on mood, cognitive functioning, and academic performance. It is unlikely that Courtney is someone who does not need much sleep since the average adult requires 7-9 hours of sleep per night. It is also unlikely that she has a high GPA if she is sacrificing sleep regularly. There is no information provided to suggest that she has maintained this sleep pattern since childhood.

Question 3

Which of the following is an accurate description of the effects of zeitgebers on the body's internal clocks?​ 
A)Both the suprachiasmatic nucleus (SCN) and peripheral clocks are affected more by light than any other type of zeitgeber. 
B)The suprachiasmatic nucleus (SCN) is more affected by light, whereas the peripheral clocks are more affected by feeding patterns. 
C)The peripheral clocks are more affected by light, whereas the suprachiasmatic nucleus (SCN) is more affected by physical activity. 
D)Both the suprachiasmatic nucleus (SCN) and peripheral clocks are affected more by physical activity and feeding patterns than by light.

Accepted Answer

Zeitgebers are external cues that help regulate the body's internal rhythms, including the suprachiasmatic nucleus (SCN) and peripheral clocks. While light is the strongest zeitgeber for the SCN, feeding patterns have a stronger effect on peripheral clocks. Therefore, option B is the most accurate description of the effects of zeitgebers on the body's internal clocks.

Question 4

John travels frequently to distant parts of the globe.He believes that adjusting his mealtimes to the destination time zone is helpful in dealing with jet lag.After studying the material in your textbook,you tell John that 
A)he's wasting his time, as adjusting his mealtimes will have little if any effect on jet lag. 
B)he should expect some benefits, as his suprachiasmatic nucleus (SCN) is very responsive to changes in feeding patterns. 
C)he should expect some benefits, as his peripheral clocks should respond to changes in feeding patterns. 
D)this is a highly effective strategy, because both his SCN and peripheral clocks are highly sensitive to changes in feeding patterns.

Accepted Answer

Research suggests that adjusting meal times to the destination time zone can help alleviate jet lag by resetting the body's peripheral clocks, which are influenced by feeding patterns. While the suprachiasmatic nucleus (SCN) plays a primary role in regulating the body's master clock, it is less responsive to changes in feeding patterns than peripheral clocks. Therefore, option B is not the best choice, and option D overstates the effectiveness of this strategy. Option A is incorrect because adjusting meal times can have some beneficial effect on jet lag.

Question 5

Melatonin is secreted by the 
A)superior colliculi. 
B)suprachiasmatic nucleus (SCN). 
C)the pituitary gland. 
D)the pineal gland.

Accepted Answer

Melatonin is primarily secreted by the pineal gland, which is a small endocrine gland located in the brain. The secretion of melatonin by the pineal gland is regulated by the suprachiasmatic nucleus (SCN), which is a tiny cluster of cells in the brain that serves as the body's internal clock. The SCN receives information about light levels from the eyes and sends signals to the pineal gland to regulate the secretion of melatonin.

Question 6

Major depressive disorder with seasonal pattern is more common during the 
A)summer near the equator. 
B)winter near the equator. 
C)summer at higher latitudes. 
D)winter at higher latitudes.

Accepted Answer

Major depressive disorder with seasonal pattern, also known as seasonal affective disorder, is more common during the winter at higher latitudes due to decreased daylight and shorter days.

Question 7

Melatonin is released during the 
A)day in diurnal species and during the night in nocturnal species. 
B)day in nocturnal species and during the night in diurnal species. 
C)day in both diurnal and nocturnal species. 
D)night in both diurnal and nocturnal species.

Accepted Answer

Melatonin is primarily released during the night in both diurnal and nocturnal species, and helps to regulate the sleep-wake cycle.

Question 8

Cortisol levels are normally 
A)highest in the morning. 
B)highest midday. 
C)highest in the evening. 
D)stable throughout the day.

Accepted Answer

Cortisol levels are highest in the morning and gradually decrease throughout the day. This is because cortisol helps us wake up and become alert in the morning, and then its levels decrease as the day goes on so that we can feel more relaxed and ready for sleep at night.

Question 9

-The labeled number 2 in this illustration indicates the​ 
A)suprachiasmatic nucleus (SCN). 
B)preoptic area (POA). 
C)retina. 
D)basal forebrain.

Accepted Answer

The answer of 
-The labeled number 2 in this illustration...

Question 10

-In fruit flies,levels of the proteins per and tim are highest during which of the stages illustrated in this figure? 
A)Number 1 
B)Number 2 
C)Number 3 
D)Number 4

Accepted Answer

The answer of 
-In fruit flies,levels of the proteins per...

Question 11

Jessica just watched an extremely scary video with her friends and is now finding it very difficult to get to sleep,even though she knows that she is very tired.It is most likely that Jessica's sleeplessness is related to increases in the release of 
A)melatonin.   
B)cortisol.   
C)dopamine. 
D)acetylcholine.

Accepted Answer

Cortisol is known as the stress hormone and increases in response to frightening or stressful situations. Therefore, it is likely that Jessica's difficulty in sleeping is related to an increase in cortisol release due to the scary video she watched. Melatonin, on the other hand, is a hormone that helps regulate sleep-wake cycles and is actually decreased by exposure to bright light (like the light emitted from screens). Dopamine and acetylcholine are neurotransmitters that are not directly related to sleep regulation.

Question 12

As per and tim proteins degrade over time,​ 
A)the clock protein is inhibited, leading to greater production of per and tim. 
B)the clock protein is activated, leading to greater production of per and tim. 
C)more melatonin is released by the pineal gland, leading to greater production of per and tim. 
D)the suprachiasmatic nucleus (SCN) is inhibited, leading to less production of per and tim.

Accepted Answer

As per and tim proteins degrade over time, the clock protein is activated, leading to greater production of per and tim. This is because the decrease in per and tim levels removes their inhibitory effect on the clock protein, allowing it to activate transcription of per and tim again. This creates a feedback loop that maintains the circadian rhythm.

Question 13

In fruit flies,per and tim proteins:​ 
A)inhibit the clock protein. 
B)promote the production of the clock protein. 
C)are inhibited by the clock protein. 
D)inhibit the production of each other and the clock protein.

Accepted Answer

PER and TIM proteins inhibit the clock protein.

Question 14

The stress of crossing multiple time zones during air travel may 
A)increase the release of melatonin. 
B)decrease the release of melatonin. 
C)increase the release of cortisol. 
D)decrease the release of cortisol.

Accepted Answer

The answer of The stress of crossing multiple time zones...

Question 15

Great Aunt Mary has always been a "lark," getting up early,working busily during the day and then going to bed relatively early.She recently had a slight stroke,and the only thing that seems different about her is that her normal periods of sleeping and waking have changed.Now,you never know when she will get up or when she will go to bed,and she is often up half the night but sleeping during the day.Given what you have learned about sleep and waking,which one of the following brain areas might have been affected by her stroke?​ 
A)the rubrospinal tract 
B)the retinohypothalamic pathway 
C)the mesolimbicstriatal pathway 
D)the thalamopituitary pathway

Accepted Answer

The retinohypothalamic pathway is responsible for regulating the sleep-wake cycle by receiving signals from the retina and communicating with the suprachiasmatic nucleus (SCN) in the hypothalamus. If this pathway is affected, it could result in changes to the sleep-wake cycle, such as unpredictable periods of sleep and wakefulness.

Question 16

A blood clot recently formed in the suprachiasmatic nucleus of Sam's hypothalamus.Fortunately,the clot was contained and he seems to be doing very well.However,there has been a change in his behavior.What might you expect that change to be?​ 
A)He has problems remembering names and faces. 
B)His vision is slightly blurred all the time. 
C)He seems to have problems with going to sleep and waking up at normal times. 
D)His muscular coordination is not as good as it used to be.

Accepted Answer

The suprachiasmatic nucleus in the hypothalamus is responsible for regulating the body's circadian rhythms, or sleep-wake cycles. Therefore, a clot in this area could lead to disruptions in normal sleep patterns.

Question 17

The suprachiasmatic nucleus (SCN)is active during the​ 
A)day for diurnal species and during the night for nocturnal species. 
B)day for nocturnal species and during the night for diurnal species. 
C)day for both diurnal and nocturnal species. 
D)night for both diurnal and nocturnal species.

Accepted Answer

The SCN is active during the day for both diurnal and nocturnal species, as it regulates circadian rhythms by responding to light cues.

Question 18

The origin of the SCN's rhythms may be​ 
A)exposure to the mother's rhythms in utero. 
B)input from the retinohypothalamic tract. 
C)exposure to melatonin. 
D)oscillations of protein production and degradation.

Accepted Answer

The answer of The origin of the SCN's rhythms may...

Question 19

Release of melatonin is suppressed by 
A)exposure of the animal to light. 
B)exposure of the animal to darkness. 
C)input from peripheral clocks. 
D)input from the superior colliculi.

Accepted Answer

Melatonin release is suppressed by exposure to light, as the hormone is primarily released during periods of darkness to aid in regulating the sleep-wake cycle.

Question 20

StStephanie,who lives in California,is preparing to compete in track and field at the Olympics in London. She plans to arrive in Londonephanie,who lives in California,is preparing to compete in track and field at the Olympics in London. She plans to arrive in London​ 
A)two weeks before competing, because her peripheral clocks in her muscles and lungs take longer than her suprachiasmatic nucleus (SCN) to adjust to a new time zone. 
B)two weeks before competing, because her SCN requires this time in order to adjust to the new time zone. 
C)a couple of days before competing, because her SCN and peripheral clocks only require a short time to adjust to the new time zone. 
D)a couple of days before competing, because eastern travel is easier on her SCN and peripheral clocks than the western travel she experienced competing in Beijing.

Accepted Answer

Stephanie should arrive two weeks before competing because her peripheral clocks in her muscles and lungs take longer than her suprachiasmatic nucleus (SCN) to adjust to a new time zone. This is supported by research that shows that it takes on average one day to adjust to a one-hour time difference when traveling westward, but it takes about 1.5 days to adjust to a one-hour time difference when traveling eastward. Arriving two weeks before competing should give Stephanie enough time to adjust her peripheral clocks to the new time zone and perform at her best.

Quiz 11: Sleep and Waking

If suprachiasmatic nucleus (SCN) tissue is transplanted from a short-period hamster into a normal hamster,

Courtney believes that pulling regular "all-nighters" is an important part of being a college student and she frequently goes all night without any sleep at all.Given what you know about sleep cycles and sleep deprivation,what else can you assume about Courtney?

Which of the following is an accurate description of the effects of zeitgebers on the body's internal clocks?

John travels frequently to distant parts of the globe.He believes that adjusting his mealtimes to the destination time zone is helpful in dealing with jet lag.After studying the material in your textbook,you tell John that

Melatonin is secreted by the

Major depressive disorder with seasonal pattern is more common during the

Melatonin is released during the

Cortisol levels are normally

-The labeled number 2 in this illustration indicates the

-In fruit flies,levels of the proteins per and tim are highest during which of the stages illustrated in this figure?

Jessica just watched an extremely scary video with her friends and is now finding it very difficult to get to sleep,even though she knows that she is very tired.It is most likely that Jessica's sleeplessness is related to increases in the release of

As per and tim proteins degrade over time,

In fruit flies,per and tim proteins:

The stress of crossing multiple time zones during air travel may

A blood clot recently formed in the suprachiasmatic nucleus of Sam's hypothalamus.Fortunately,the clot was contained and he seems to be doing very well.However,there has been a change in his behavior.What might you expect that change to be?

The suprachiasmatic nucleus (SCN) is active during the

The origin of the SCN's rhythms may be

Release of melatonin is suppressed by

StStephanie,who lives in California,is preparing to compete in track and field at the Olympics in London. She plans to arrive in Londonephanie,who lives in California,is preparing to compete in track and field at the Olympics in London. She plans to arrive in London

Quiz 11: Sleep and Waking

If suprachiasmatic nucleus (SCN) tissue is transplanted from a short-period hamster into a normal hamster,​