Answer:
There are two types of cell membranes. Either open or closed. Open is when other particles can get in or out. Closed is the opposite.
I hope that helps!
It is a perfect example of a natural selection.
(I'm not sure if this is the exact answer that you are looking for.)
True the asnwer is trueeeeeee
Using statistics.
Make a tree diagram - probability adds up to 1
