Introduction to Behavioral Neuroscience Instructor Answer Guide
Multiple Choice
15.1 What Are Circadian Rhythms?
1. Female rats have an estrous cycle that determines when they are sexually receptive to a
mate. This cycle repeats every ~4 days. What kind of biological rhythm is this?
a. Ultradian
b. Circadian
c. Infradian
d. Circannual
Answer: c
2. Biological rhythms can have a period of:
a. a few hours.
b. ~24 hours.
c. more than 24 hours.
d. All of these
Answer: d
3. Every day, Eli’s alarm goes off at 6am. He hits snooze and usually does not wake up until
8am. The 2h difference between his alarm and when Eli wakes up is called a:
a. phase difference.
b. period.
c. amplitude.
d. phase.
Answer: a
4. Biological rhythms are regulated by:
a. endogenous cues.
b. exogenous cues.
c. both endogenous and exogenous cues.
d. neither endogenous nor exogenous cues.
Answer: c
5. When laboratory rodents are shifted to live in constant darkness, they still show a 24h
rhythm in their activity levels. We call their rhythm in these conditions:
a. entrained.
b. free-running.
, Introduction to Behavioral Neuroscience Instructor Answer Guide
c. chronotype.
d. photically shifted.
Answer: b
6. When laboratory rodents are shifted to live in constant darkness, they still show a 24h
rhythm in their activity levels. If we were to expose an animal like this to a pulse of light in
the first half of their subjective night, what would happen to their activity rhythm?
a. Their activity rhythm would shift earlier a bit
b. Their activity rhythm would shift later a bit
c. Not much would happen
d. Their rhythm would become disorganized
Answer: b
7. Which of the following species show a circadian rhythm?
a. Rats
b. Bacteria
c. Plants
d. All of these
Answer: d
15.2 Where Are Rhythms in the Brain?
8. Entrainment of the biological clock by light requires which of the following?
a. Photoreceptors
b. Intrinsically photosensitive retinal ganglion cells
c. Red light
d. The lateral geniculate nucleus of the thalamus
Answer: b
9. Imagine a rodent has a small stroke that destroys their bilateral SCN. What would
happen to their activity rhythm?
a. Their activity rhythm would shift earlier a bit
b. Their rhythm would continue but would no longer entrain to changes in external
light cues
c. Not much would happen
d. Their rhythm would become disorganized
Answer: d
10. Increased locomotor activity:
a. increases serotonin release in the raphe nuclei.
2
Updated October 2024
Multiple Choice
15.1 What Are Circadian Rhythms?
1. Female rats have an estrous cycle that determines when they are sexually receptive to a
mate. This cycle repeats every ~4 days. What kind of biological rhythm is this?
a. Ultradian
b. Circadian
c. Infradian
d. Circannual
Answer: c
2. Biological rhythms can have a period of:
a. a few hours.
b. ~24 hours.
c. more than 24 hours.
d. All of these
Answer: d
3. Every day, Eli’s alarm goes off at 6am. He hits snooze and usually does not wake up until
8am. The 2h difference between his alarm and when Eli wakes up is called a:
a. phase difference.
b. period.
c. amplitude.
d. phase.
Answer: a
4. Biological rhythms are regulated by:
a. endogenous cues.
b. exogenous cues.
c. both endogenous and exogenous cues.
d. neither endogenous nor exogenous cues.
Answer: c
5. When laboratory rodents are shifted to live in constant darkness, they still show a 24h
rhythm in their activity levels. We call their rhythm in these conditions:
a. entrained.
b. free-running.
, Introduction to Behavioral Neuroscience Instructor Answer Guide
c. chronotype.
d. photically shifted.
Answer: b
6. When laboratory rodents are shifted to live in constant darkness, they still show a 24h
rhythm in their activity levels. If we were to expose an animal like this to a pulse of light in
the first half of their subjective night, what would happen to their activity rhythm?
a. Their activity rhythm would shift earlier a bit
b. Their activity rhythm would shift later a bit
c. Not much would happen
d. Their rhythm would become disorganized
Answer: b
7. Which of the following species show a circadian rhythm?
a. Rats
b. Bacteria
c. Plants
d. All of these
Answer: d
15.2 Where Are Rhythms in the Brain?
8. Entrainment of the biological clock by light requires which of the following?
a. Photoreceptors
b. Intrinsically photosensitive retinal ganglion cells
c. Red light
d. The lateral geniculate nucleus of the thalamus
Answer: b
9. Imagine a rodent has a small stroke that destroys their bilateral SCN. What would
happen to their activity rhythm?
a. Their activity rhythm would shift earlier a bit
b. Their rhythm would continue but would no longer entrain to changes in external
light cues
c. Not much would happen
d. Their rhythm would become disorganized
Answer: d
10. Increased locomotor activity:
a. increases serotonin release in the raphe nuclei.
2
Updated October 2024
