Answer: Clock in the skin cells is called circadian clock.
Explanation:
Circadian clock is a system that requlates how the skin function and human physiology. The stem cells of basal epidermal harbors circadian clock.Circadian clock is found in some skin cells like melanocytes, keratinocytes and fibroblasts. Circadian clock found in skin cells may function by regulating cell proliferation.
The answer is C. The symbiotic relationship has evolved for so many years such that the two are obligate symbiotes and cannot function normally without the other. Chloroplast and mitochondria are believed to have been once free-living bacteria according to endosymbiosis theory.
