A closed system is a system that makes no physical or chemical exchanges with its environment. Of these systems provided as choices (tree, human, clock, car), only a clock does not make exchanges with the environment, except for energy.
Therefore, of that list, only a clock would be a closed system.
Hope that helped! =)
All prokarytoic cells replicate through binary fission.
Answer:
The Testes.
Explanation:
Testes are contained in a sac of skin called the scrotum, it produces sperm, then make hormone testosterone. It aids testosterone which promotes the development of secondary sexual characteristics, which in humans include a deeper voice, more body hair, and more powerful muscles than that in their counterparts which are the female.
The answer is D. 90 percent
