In the context of sleep and AP Psychology, what is melatonin?

• A. A stimulant drug used to treat insomnia
• B. A protein that builds muscle during deep sleep
• C. A hormone produced by the pineal gland that helps regulate the sleep-wake cycle
• D. A neurotransmitter that increases alertness and arousal

Answer: (C)

Verified step by step guidance

1. Understand that melatonin is related to the regulation of sleep, which is a key topic in AP Psychology when studying biological rhythms and the sleep-wake cycle.
2. Recall that melatonin is not a stimulant drug, so eliminate the option describing it as a stimulant used to treat insomnia.
3. Recognize that melatonin is not a protein involved in muscle building during sleep, so eliminate the option about it being a protein.
4. Know that melatonin is a hormone produced by the pineal gland, which plays a crucial role in signaling the body when it is time to sleep by regulating the circadian rhythm.
5. Understand that melatonin is not a neurotransmitter that increases alertness; instead, it promotes sleepiness and helps manage the sleep-wake cycle.