Explain what process the a cell must use to allow a protein to enter and why?

The process the cell must use to allow the protein to enter is rather simple and uncomplicated. The cell uses the process of osmosis and diffusion along a concentration gradient to allow for passage in and out of the cell.

what's the question ?

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.