a. allow a variety of molecules to cross the cytoplasmic membrane
Explanation:
The cells have different molecules in its membrane. As a membrane the main function of it is to regulate the income and outcome of substances that the cell needs or the cell has like some wastes.
Some of these molecules can be some proteins like the permeases, that is going to regulate the solutes that can enter the cell, but since they are non specific, that means that can not make the difference among one carbohydrate and another (as an example).
Not sure if theres supposed to be a pic or chart with this but if its any help, recessive traits only show when theres no dominant traits present and both parents need recessive genes
