Question 1

If the per gene is key to regulating circadian rhythms, we can predict that

Accepted Answer

A)  the per gene acts independently of neurons in the SCN to modulate daily behaviors. 
B)  the per gene must be a newly evolved mechanism that is not present in more primitive animals. 
C)  per expression should increase continuously over time if no environmental cues are provided. 
D)  animals with low per expression, and thus little PER protein production, should not have a circadian rhythm. 
A)  the per gene acts independently of neurons in the SCN to modulate daily behaviors. 
B)  the per gene must be a newly evolved mechanism that is not present in more primitive animals. 
C)  per expression should increase continuously over time if no environmental cues are provided. 
D)  animals with low per expression, and thus little PER protein production, should not have a circadian rhythm. D

Question 2

John Wingfield and his coauthors made the following statement early in their article on testosterone and the challenge hypothesis: "The prevailing 'challenge' hypothesis asserts that testosterone and aggression correlate only during periods of heightened interactions between males." This statement is a

Accepted Answer

A)  definition of the challenge hypothesis. 
B)  prediction derived from the challenge hypothesis. 
C)  statement about the evidence that supports the challenge hypothesis. 
D)  scientific conclusion. 
A)  definition of the challenge hypothesis. 
B)  prediction derived from the challenge hypothesis. 
C)  statement about the evidence that supports the challenge hypothesis. 
D)  scientific conclusion. B

Question 3

What is a photoperiod?

Accepted Answer

A)  The duration of light in 24 hours 
B)  The period of light in 12-hour intervals 
C)  The increase in light over a series of 24-hour periods 
D)  The variation in light that occurs during daytime 
A)  The duration of light in 24 hours 
B)  The period of light in 12-hour intervals 
C)  The increase in light over a series of 24-hour periods 
D)  The variation in light that occurs during daytime A

Question 4

Refer to the figure.
  In this graph of marine iguana foraging start times, what pattern emerges between when iguanas forage in the intertidal zone versus the subtidal zone?

Accepted Answer

A)  Marine iguanas switch every few weeks between foraging in the intertidal zone throughout the day, and only foraging in the subtidal zone around midday. 
B)  Marine iguanas forage equally between the intertidal and subtidal zone at any time of day. 
C)  Marine iguanas initially forage primarily in the intertidal zone but switch to foraging in the subtidal zone as temperatures get cooler. 
D)  Marine iguanas switch between foraging in the intertidal zone at night, and the subtidal zone during the middle of the day. 
A)  Marine iguanas switch every few weeks between foraging in the intertidal zone throughout the day, and only foraging in the subtidal zone around midday. 
B)  Marine iguanas forage equally between the intertidal and subtidal zone at any time of day. 
C)  Marine iguanas initially forage primarily in the intertidal zone but switch to foraging in the subtidal zone as temperatures get cooler. 
D)  Marine iguanas switch between foraging in the intertidal zone at night, and the subtidal zone during the middle of the day.

Question 5

Refer to the figure.
  What environmental cues are the iguanas using to regulate their foraging behavior?

Accepted Answer

A)  Lunar cycles and availability of moonlight 
B)  Changes in daily temperature and day length 
C)  The interaction between diurnal and tidal cycles 
D)  Rainfall and changes in food availability 
A)  Lunar cycles and availability of moonlight 
B)  Changes in daily temperature and day length 
C)  The interaction between diurnal and tidal cycles 
D)  Rainfall and changes in food availability

Question 6

In a study on golden-mantled ground squirrels from North America, young raised in an environment with constant darkness and temperature entered into hibernation the same time each year. In a similar study on stonechats from Kenya, offspring raised in an environment with constant temperature and photoperiod maintained an annual reproductive cycle, but this cycle shifted out of phase over time. What information about the two species' environments most likely explains this difference in experimental results between the squirrels and stonechats?

Accepted Answer

Kenya is an arid, unpredictable environm

Question 7

Refer to the figure.
  This figure shows the hourly changes in the production of messenger RNA (mRNA) encoded by the PK2 gene in mice exposed to a light-dark cycles of 12 hours of light and 12 hours of darkness (LD), complete darkness for 2 days (2DD), and complete darkness for 8 days (8DD). How do these results support the hypothesis that PK2 is a clock messenger?

Accepted Answer

A)  The production of PK2 depends on the amount of daylight that is available. 
B)  PK2 is produced in a circadian pattern independent of light-dark cues. 
C)  A mutation in certain key clock genes disrupts the circadian rhythm of PK2 production. 
D)  Prolonged periods of darkness increase the expression of the gene that produces PK2. 
A)  The production of PK2 depends on the amount of daylight that is available. 
B)  PK2 is produced in a circadian pattern independent of light-dark cues. 
C)  A mutation in certain key clock genes disrupts the circadian rhythm of PK2 production. 
D)  Prolonged periods of darkness increase the expression of the gene that produces PK2.

Question 8

Refer to the figure.
  The bottom figure's findings best support the proximate-level hypothesis that

Accepted Answer

A)  crickets use the light and dark as environmental cues to entrain their circadian rhythm. 
B)  crickets have an internal clock that maintains a regular cycle of calling in the absence of environmental cues. 
C)  it is adaptive for male crickets to have a circadian rhythm in order to match female activity and increase chances of reproduction. 
D)  the molecule juvenile hormone (JH) is responsible for regulating the cricket's circadian rhythm. 
A)  crickets use the light and dark as environmental cues to entrain their circadian rhythm. 
B)  crickets have an internal clock that maintains a regular cycle of calling in the absence of environmental cues. 
C)  it is adaptive for male crickets to have a circadian rhythm in order to match female activity and increase chances of reproduction. 
D)  the molecule juvenile hormone (JH) is responsible for regulating the cricket's circadian rhythm.

Question 9

Testosterone is apparently a very costly hormone for males to produce and use. Why, then, has natural selection resulted in the males of some many species investing in the production and use of this hormone?

Accepted Answer

A)  Because natural selection cannot override the effects of shared ancestry-because male animals share a common ancestor that used testosterone adaptively, they continue to do so today 
B)  Because testosterone helps ensure that males will be motivated to search for and to find all the receptive females of their species, thereby increasing the odds that the females will all be able to produce some offspring 
C)  Because under a variety of circumstances, the hormone makes is possible for males to be either aggressive or sexually motivated in ways that increase individual genetic success 
D)  Because males that are able to pay the price for producing and using testosterone are demonstrating that they are able to overcome this handicap, which means that they are genetically worthy members of the breeding stock for their population 
A)  Because natural selection cannot override the effects of shared ancestry-because male animals share a common ancestor that used testosterone adaptively, they continue to do so today 
B)  Because testosterone helps ensure that males will be motivated to search for and to find all the receptive females of their species, thereby increasing the odds that the females will all be able to produce some offspring 
C)  Because under a variety of circumstances, the hormone makes is possible for males to be either aggressive or sexually motivated in ways that increase individual genetic success 
D)  Because males that are able to pay the price for producing and using testosterone are demonstrating that they are able to overcome this handicap, which means that they are genetically worthy members of the breeding stock for their population

Question 10

The occurrence of heightened chronic stress can cause an individual to produce and continue to release stress hormones, such as glucocorticoids, that eventually damage the affected individual's immune system. Why has such an obviously costly response evolved?

Accepted Answer

Perhaps because under brief, acute stres

Question 11

Apply the reproductive readiness hypothesis to explain why some songbirds are able to respond to environmental conditions suitable for raising offspring, even when the conditions are presented outside of the traditional breeding season. What is the ultimate explanation for the birds' response?

Accepted Answer

Some songbird species have been observed

Question 12

After a dry spring, rufous-winged sparrows in the Sonoran Desert wait for summer rainfall to stimulate the onset of reproduction. Sparrows likely use rainfall as an environmental cue because

Accepted Answer

A)  rainfall is a predictable cue that ensures that they are primed for reproduction at the same time every year. 
B)  they live near the equator and the small changes in photoperiod are too difficult to use as a cue for reproduction. 
C)  the onset of the monsoon in the summer determines when sparrows migrate north for the breeding season. 
D)  they live in an arid, unpredictable environment where rainfall provides a more informative cue for resource availability and reproductive timing. 
A)  rainfall is a predictable cue that ensures that they are primed for reproduction at the same time every year. 
B)  they live near the equator and the small changes in photoperiod are too difficult to use as a cue for reproduction. 
C)  the onset of the monsoon in the summer determines when sparrows migrate north for the breeding season. 
D)  they live in an arid, unpredictable environment where rainfall provides a more informative cue for resource availability and reproductive timing.

Question 13

Refer to the figure.
  Top: An illustration of the single plotted actogram depicts the circadian rhythm of calling in Australian black field cricket during the day schedule, which shows the male crickets were kept constant in light for 24 hours. Bottom: An illustration of the single plotted actogram depicts the circadian rhythm of calling in Australian black field cricket during the day and night schedule, which shows the male crickets were kept constant in light for 12 hours and the next 12 hours, male crickets were subjected to dark.
The bottom figure demonstrates that in an alternating light and dark environment, male crickets

Accepted Answer

A)  are unable to maintain a regular cycle of calling. 
B)  call continuously throughout the day due to the constant light input. 
C)  maintain a daily cycle of calling and noncalling that starts slightly later each day. 
D)  reset their calling cycle to start a few hours before the lights go off and continue until a few hours before the lights go on. 
A)  are unable to maintain a regular cycle of calling. 
B)  call continuously throughout the day due to the constant light input. 
C)  maintain a daily cycle of calling and noncalling that starts slightly later each day. 
D)  reset their calling cycle to start a few hours before the lights go off and continue until a few hours before the lights go on.

Question 14

Refer to the figure.
  In these figures, each horizontal line represents 1 day, and each vertical line represents a half-hour on a 24-hour timescale. Dark marks indicate periods of cricket calling. The bars at the top and middle represent the lighting conditions. The top figure demonstrates that in a constant light (LL) environment, male crickets

Accepted Answer

A)  are unable to maintain a regular cycle of calling. 
B)  call continuously throughout the day due to the constant light input. 
C)  maintain a daily cycle of calling and noncalling that starts slightly later each day. 
D)  reset their calling cycle to start a few hours before the lights go off and continue until a few hours before the lights go on. 
A)  are unable to maintain a regular cycle of calling. 
B)  call continuously throughout the day due to the constant light input. 
C)  maintain a daily cycle of calling and noncalling that starts slightly later each day. 
D)  reset their calling cycle to start a few hours before the lights go off and continue until a few hours before the lights go on.

Question 15

Refer to the figure.
   Describe an experiment to test the hypothesis that PK2 is a key clock messenger responsible for regulating circadian behaviors. Base your experiment on the results shown below, which show activity levels for rats in two treatment groups. Explain your predictions if the hypothesis is supported, and if the hypothesis is not supported. Note that rats are usually active during the nighttime, and PK2 production is normally high during the daytime and low during the nighttime.

Accepted Answer

To test the role of PK2 on circadian rhy

Question 16

Describe an example of a species that uses a predictable environmental cue other than photoperiodism to determine either circadian or circannual rhythms. Specify the species, the environmental cue it uses, and the behavioral rhythm that changes based on that cue.

Accepted Answer

From the textbook, possible answers incl

Question 17

Refer to the figure.
  The top figure's findings best support the proximate-level hypothesis that

Accepted Answer

A)  crickets use the light and dark as environmental cues to entrain their circadian rhythm. 
B)  crickets have an internal clock that maintains a regular cycle of calling in the absence of environmental cues. 
C)  it is adaptive for male crickets to have a circadian rhythm in order to match female activity and increase chances of reproduction. 
D)  the molecule juvenile hormone (JH) is responsible for regulating the cricket's circadian rhythm. 
A)  crickets use the light and dark as environmental cues to entrain their circadian rhythm. 
B)  crickets have an internal clock that maintains a regular cycle of calling in the absence of environmental cues. 
C)  it is adaptive for male crickets to have a circadian rhythm in order to match female activity and increase chances of reproduction. 
D)  the molecule juvenile hormone (JH) is responsible for regulating the cricket's circadian rhythm.

Question 18

Refer to the figure
  The most significant feature of this record for persons studying circadian rhythms is the

Accepted Answer

A)  demonstration that this species has a 24-hour circadian rhythm. 
B)  absence of a circadian rhythm under the special conditions of the experiment. 
C)  randomness in the time at which daily activity began. 
D)  persistence of an activity period in the absence of daily environmental cues. 
A)  demonstration that this species has a 24-hour circadian rhythm. 
B)  absence of a circadian rhythm under the special conditions of the experiment. 
C)  randomness in the time at which daily activity began. 
D)  persistence of an activity period in the absence of daily environmental cues.

Question 19

Refer to the figure.
  These results, showing the change in testis length in male red crossbills over time, support the hypothesis that crossbills

Accepted Answer

A)  are reproductively opportunistic birds that maintain full reproductive capacity throughout the year. 
B)  have an underlying reproductive cycle that is dependent on photoperiod. 
C)  only use seed abundance, an unpredictable environmental cue, to determine reproductive capacity. 
D)  do not rely on environmental cues to entrain their reproductive cycle. 
A)  are reproductively opportunistic birds that maintain full reproductive capacity throughout the year. 
B)  have an underlying reproductive cycle that is dependent on photoperiod. 
C)  only use seed abundance, an unpredictable environmental cue, to determine reproductive capacity. 
D)  do not rely on environmental cues to entrain their reproductive cycle.

Question 20

The naked mole rat lacks a circadian rhythm of activity. The ultimate adaptive significance of this point is that

Accepted Answer

A)  because naked mole rats live underground, they are not exposed to daily changes in light intensity and thus have no cues for the entrainment of a circadian rhythm. 
B)  the environment of the naked mole rat is such that queens and kings gain no reproductive advantage by having a sterile work force that is active on a 24-hour schedule. 
C)  naked mole rats are primitive mammals that do not have the sophisticated mechanisms that control circadian rhythms. 
D)  naked mole rats do not have the genetic information that would enable them to develop a brain capable of circadian rhythms. 
A)  because naked mole rats live underground, they are not exposed to daily changes in light intensity and thus have no cues for the entrainment of a circadian rhythm. 
B)  the environment of the naked mole rat is such that queens and kings gain no reproductive advantage by having a sterile work force that is active on a 24-hour schedule. 
C)  naked mole rats are primitive mammals that do not have the sophisticated mechanisms that control circadian rhythms. 
D)  naked mole rats do not have the genetic information that would enable them to develop a brain capable of circadian rhythms.

If the per gene is key to regulating circadian rhythms, we can predict that

What is a photoperiod?

Refer to the figure. In this graph of marine iguana foraging start times, what pattern emerges between when iguanas forage in the intertidal zone versus the subtidal zone?

Refer to the figure. What environmental cues are the iguanas using to regulate their foraging behavior?

Refer to the figure. The bottom figure's findings best support the proximate-level hypothesis that

Testosterone is apparently a very costly hormone for males to produce and use. Why, then, has natural selection resulted in the males of some many species investing in the production and use of this hormone?

The occurrence of heightened chronic stress can cause an individual to produce and continue to release stress hormones, such as glucocorticoids, that eventually damage the affected individual's immune system. Why has such an obviously costly response evolved?

Apply the reproductive readiness hypothesis to explain why some songbirds are able to respond to environmental conditions suitable for raising offspring, even when the conditions are presented outside of the traditional breeding season. What is the ultimate explanation for the birds' response?

After a dry spring, rufous-winged sparrows in the Sonoran Desert wait for summer rainfall to stimulate the onset of reproduction. Sparrows likely use rainfall as an environmental cue because

Describe an example of a species that uses a predictable environmental cue other than photoperiodism to determine either circadian or circannual rhythms. Specify the species, the environmental cue it uses, and the behavioral rhythm that changes based on that cue.

Refer to the figure. The top figure's findings best support the proximate-level hypothesis that

Refer to the figure The most significant feature of this record for persons studying circadian rhythms is the

Refer to the figure. These results, showing the change in testis length in male red crossbills over time, support the hypothesis that crossbills

The naked mole rat lacks a circadian rhythm of activity. The ultimate adaptive significance of this point is that

An Introduction to Animal Behavior

The Integrative Study of Behavior

The Developmental and Molecular Bases of Behavior

The Neural Basis of Behavior

Avoiding Predators and Finding Food

Territoriality and Movement

Principles of Communication

Reproductive Behavior

Mating Systems

Parental Care

Principles of Social Evolution

Social Behavior and Sociality

Human Behavior

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Exam 5: The Physiological and Endocrine Basis of Behavior

If the per gene is key to regulating circadian rhythms, we can predict that

What is a photoperiod?

Refer to the figure. In this graph of marine iguana foraging start times, what pattern emerges between when iguanas forage in the intertidal zone versus the subtidal zone?

Refer to the figure. What environmental cues are the iguanas using to regulate their foraging behavior?

Refer to the figure. The bottom figure's findings best support the proximate-level hypothesis that

Testosterone is apparently a very costly hormone for males to produce and use. Why, then, has natural selection resulted in the males of some many species investing in the production and use of this hormone?

The occurrence of heightened chronic stress can cause an individual to produce and continue to release stress hormones, such as glucocorticoids, that eventually damage the affected individual's immune system. Why has such an obviously costly response evolved?

Apply the reproductive readiness hypothesis to explain why some songbirds are able to respond to environmental conditions suitable for raising offspring, even when the conditions are presented outside of the traditional breeding season. What is the ultimate explanation for the birds' response?

After a dry spring, rufous-winged sparrows in the Sonoran Desert wait for summer rainfall to stimulate the onset of reproduction. Sparrows likely use rainfall as an environmental cue because

Describe an example of a species that uses a predictable environmental cue other than photoperiodism to determine either circadian or circannual rhythms. Specify the species, the environmental cue it uses, and the behavioral rhythm that changes based on that cue.

Refer to the figure. The top figure's findings best support the proximate-level hypothesis that

Refer to the figure The most significant feature of this record for persons studying circadian rhythms is the

Refer to the figure. These results, showing the change in testis length in male red crossbills over time, support the hypothesis that crossbills

The naked mole rat lacks a circadian rhythm of activity. The ultimate adaptive significance of this point is that

An Introduction to Animal Behavior

The Integrative Study of Behavior

The Developmental and Molecular Bases of Behavior

The Neural Basis of Behavior

Avoiding Predators and Finding Food

Territoriality and Movement

Principles of Communication

Reproductive Behavior

Mating Systems

Parental Care

Principles of Social Evolution

Social Behavior and Sociality

Human Behavior

Filters