ami tellement désolé tellement je ne connais pas cette langue mais salut mon ami
The main purpose is protection. The lipid bilayer protects the cell from viruses and other threats to the cell. It also maintains homeostasis within the cell by monitoring the amount of substances the enter or exit the cell.
The answer is; D
It reduces the diversity of the population because some variations in the population can be completely eliminated by the bottleneck effect. Even if the population recovers in population size, the genetic variation will have reduced as compared to the initial population before the bottleneck. For a mall population, this effect can be grave because the reduced genetic variation may mean that the population may be unable to adapt to new selection pressures hence may go extinct.
In prophase the chromatin condenses into chromosomes.