Question

Which of these glands produce a hormone that is believed to affect the sleep cycle? Pineal body Thymus Ovaries Testes

Answer 1

Melatonin is created in the pineal gland, hope this helps!

Answer 2

Pineal which is also called thalamus, this gland produces hormone serotonin, that greatly affects sleep cycle. While the rest of the glands; thymus is related to immune functions, and ovaries and testes produce sex hormones mainly.