Answer:
The skin is an organ of protection
Explanation:
The primary function of the skin is to act as a barrier. The skin provides protection from: mechanical impacts and pressure, variations in temperature, micro-organisms, radiation and chemicals.
The sled with a rough metal bottom would take more force to move over ice, because the rough surface would increase friction and the force needed.
When they reach size limitations....they divide by binary fission or any other process of reproduction !
second may be they stop division and stay at their state as happens in ovum of the female as they stops in diakinesis !!!
One sperm fertilizes the egg cell forming a diploid zygote, the other sperm fuses with the two polar nuclei forming a triploid cell that develops into endosperm