I think this would be the environment. That's my guess
Answer:
some traits become more common, others less. ... The traits that become more common are the ones that are “adaptive” or “increase fitness” (that is, a creature's chances of living longer and producing more offspring).
What on earth, please repeat the question clearer
Answer: Read explanation
Explanation: there’s actually no similarity at all. A cell membrane is made of phospholipids, globular proteins, glycolipids, glycoproteins, and cholesterol, and has passages that serve explicitly for passive and active transport of materials through it.
The skin is made of cells and dead keratin and serves as much as possible to prevent most substances from moving through it. It’s “designed” for toughness and distensibility, not for selective permeability.
All in all, the difference is that a cell membrane is explicitly and only for the passing and transport of materials through it, and the skin in the skin is made to be tough and durable, almost the opposite of a cell membrane.
Answer:
Microtubules play an important role in cell division by contributing to the formation of the mitotic spindle, which plays a part in the migration of duplicated chromosomes during anaphase.