Describe the external environment when melatonin levels are highest in the body in the 24-hour cycle

Dark and quiet, around 2-4AM

Explanation:

Melatonin is induced by darkness (i.e. when the sun goes down) but the levels reach a peak in the middle of the sleep cycle around 2-4AM, then begin to gradually fall.

it's the cell cycle, but cytokines is when the cell divides.

theres 3 stages interphase,mitosis,and cytokines.

interphase prepares the cell for division.

mitosis is the process of dividing the cell,it has 4 parts interphase,anaphase,metaphase,and telophase.

lastly there's cytokines,that's when the cell divides into 2 daughter cells