Final answer:
The biological clock in the hypothalamus is called the suprachiasmatic nucleus (SCN), which coordinates the body's circadian rhythms with external light cues and maintains homeostasis.
Step-by-step explanation:
The region of the hypothalamus that acts as a biological clock is known as the suprachiasmatic nucleus (SCN). This small region of the brain receives information from light-sensitive neurons in the retina and synchronizes the body's circadian rhythms with the external environment. Most bodily functions, including sleep-wake cycles and hormonal fluctuations, are influenced by these rhythms. The SCN plays a crucial role in homeostasis by integrating various signals, such as light and hormonal feedback, to maintain the body's internal balance in coordination with the external world.
The hypothalamus overall is involved in a range of functions from regulating the autonomic nervous system to emotional regulation as part of the limbic system. It also influences the endocrine system through its control of the anterior pituitary gland and participates in temperature regulation and memory formation.