Exam 9: Biological Clocks

When the SCN was isolated from neural input by a knife cut that created an island of hypothalamic tissue, the neural activity in the hypothalamic island

The fiddler crab (Uca pugnax) alternates periods of activity with periods of quiescence every 12.4 hours. This pattern is typical of an animal whose activity cycles are synchronized with

Some birds experience significant changes in body mass and size of testes. These are changes that typically occur according to a(n)

The biological clock remains accurate in spite of large changes in environmental temperature.

Entraining a biological clock means

In mammals, the rhythmic production of two hormones, _______, are thought to be important in entraining peripheral oscillators.

An individual animal may have many biological clocks scattered throughout its body.

A defining characteristic of biological clock-controlled rhythms is that cycles

DeCoursey and colleagues (1997) destroyed the SCN of some antelope ground squirrels (Ammospermophilus leucurus) and compared their survival rate outdoors to that of intact animals. They found that

If a nocturnal laboratory subject that is being maintained under conditions of constant darkness experiences a brief light pulse early during its circadian night, it will

DeCoursey and colleagues (2000) compared survival rates of three groups of eastern chipmunks (Tamias striatus): an SCN-lesioned group, a sham-lesioned group, and an intact, control group. They found that

A worker honeybee indicates the direction to a nectar source through a dance that tells them of the proper flight bearing relative to the sun, even if the nectar source was discovered earlier in the day. The dancing bee is best exemplifying which of the following advantages of clock-controlled behavior?

If you have asthma, you are most likely to suffer an attack

Entrainment of the biological clock is especially important for animals living

An animal that is active primarily at dawn and dusk would be described as

The genetic basis for the circadian cycle involves a loop of gene activity: the Clock/Bmal1 complex turns on the activity of both per and cry genes; products from these bind with a protein product of the tau gene; the per/cry/tau complex suppresses the action of the Clock/Bmal1 complex, etc. This cycle takes about _____ hour(s) to complete.

Honeybees fly to flowers for nectar that they have learned are open only during restricted times of the day, even though the flowers are far from the hive. The honeybees are best exemplifying which of the following advantages of clock-controlled behavior?

Silver and colleagues (1996) conducted transplant experiments in which hamster donor SCN tissue was enclosed within a capsule before being transplanted into a host hamster whose clocks ran at different rates.

Which of the following statements regarding biological clocks is FALSE?

The experiments with glowing fruit flies demonstrated that