Question 1

How long ago was reliable evidence for the existence of endogenous (internal) 24-hour rhythmicity first recorded
in an animal?

A. 1 year

B. 10 years

C. 25 years

D. 50 years

E. 100 years


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Question 2

The word "circadian" was not created until the 1950's. Who introduced the word?

A. Colin Pittendrigh

B. Franz Halberg

C. Jürgen Aschoff

D. Albert Einstein

E. Jean-Jacques de Mairan


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Question 3

Which of the following descriptions does not apply to circadian rhythmicity?

A. A process that can be found in bacteria, plants, fungi, and animals

B. A process that cycles in intervals of approximately 24 hours

C. A process that is rhythmic only in the presence of environmental cycles

D. A process that can be synchronized by environmental cycles

E. A process that can be disrupted by prolonged exposure to constant darkness


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Question 4

What is an "actogram"?

A. A unit of mass equivalent to 10^-15 grams

B. A machine that records circadian rhyhms

C. A cyclic nightmare

D. A plot of activity over time

E. A plant used in early studies of circadian rhythms


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Question 5

A woman's menstrual cycle is an example of

A. Circadian rhythm

B. Infradian rhythm

C. Ultradian rhythm

D. All of the above

E. None of the above


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Question 6

What is a "race tube"?

A. An inflatable float used in water-park rides

B. A device for monitoring running speed of mice

C. A cylinder with white, yellow, and brown bands

D. A device for the monitoring of microbial growth

E. None of the above


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Question 7

The period (cycle length) of circadian rhythms is determined

A. Mostly by nature (genetic inheritance)

B. Mostly by nurture (history of environmental exposure)

C. Equally by nature and nurture

D. By neither nature nor nurture

E. All of the above


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Question 8

According to the "non-parametric theory of entrainment", entrainment (synchronization) of circadian rhythms by environmental stimuli is achieved by

A. The slowing down or speeding up of the clock

B. Unknown parameters

C. Discrete daily phase shifts

D. Little green men hiding behind the bushes

E. Genetic mutation


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Question 9

What is "food-anticipatory activity"?

A. The preprandial secretion of insulin

B. The postprandial secretion of saliva

C. The expression of displeasure about a meal

D. A psychological phenomenon related to expectation of outcomes

E. A behavioral pattern typical of entrainment by food restriction schedules


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Question 10

How long ago is circadian rhythmicity believed to have evolved?

A. Several trillion years

B. Several billion years

C. Several million years

D. Several thousand years

E. Several hundred years


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Question 11

Why are nocturnal organisms active at night?

A. Because their eyes are specialized for night vision

B. Because their circadian system is unresponsive to light

C. Because their active phase is genetically timed to subjective night

D. A and C

E. B and C


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Question 12

Sleep is controlled

A. By a homeostatic (restorative) system

B. By the circadian system

C. By both a homeostatic system and the circadian system

D. By neither a homeostatic system nor the circadian system

E. By elves hidden in the brain


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Question 13

The circadian system of mammals is sensitive to ambient illumination that reaches

A. The rods and cones in the retina of the eye

B. Specialized photosensitive ganglion cells in the retina

C. The skin

D. A and C

E. A and B


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Question 14

The "master circadian pacemaker" in the mammalian brain is located in the

A. Suprachiasmatic nucleus

B. Preoptic area

C. Thalamus

D. Hippocampus

E. Visual cortex


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Question 15

The suprachiasmatic nucleus can be anatomically and functionally subdivided into two regions. These two regions differ because

A. One is mostly ventrally located whereas the other is mostly dorsally located

B. One is the target of many projections from extra- hypothalamic sites whereas the other is not

C. One contains many intrinsically-rhythmic neurons whereas the other contains few

D. All of the above

E. None of the above


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Question 16

The molecular mechanism responsible for circadian rhythmicity can best be characterized as

A. Being part of the cell cycle

B. Consisting of a single transcriptional loop

C. Consisting of a single translational loop

D. Being a feedbackless process

E. Consisting of one or more transcriptional/translational loops


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Question 17

Which of the following pairs of taxonomic groups and clock genes is mismatched?

A. Bacteria - kai

B. Plants - toc1

C. Fungi - bmal1

D. Invertebrates - per

E. Vertebrates - clk


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Question 18

Which of the following conditions is not common to jet lag and the malaise associated with shift work?

A. Inadequate phase relationship between the internal clock and the external cycle of sunlight and darkness

B. Inadequate phase relationship between the internal clock and the schedule of activity and rest

C. Difficulty in sleeping at the scheduled sleep time

D. Drowsiness during the scheduled work time

E. None of the above


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Question 19

A persistent phase delay of the internal clock is most likely the cause of which of these diseases?

A. Lung cancer

B. Syphilis

C. Narcolepsy

D. Sleep-onset insomnia

E. Sleep-termination insomnia


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Question 20

In a human adult, an oral temperature of 36.9 °C (98.4 °F)

A. Clearly indicates a state of fever

B. Clearly indicates the absence of fever

C. Provides no helpful information for the diagnosis of fever

D. Is suggestive of fever at night but not in the afternoon

E. None of the above


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