The correct answer is permeable membrane which is selective.
The reason why molecules may not or may be able to pass into the cell is because that the cell are permeable membranes which selects what is to enter and what is not to enter.
Molecules are termed as the group of two or more atoms which are electrically neutral, and are held together by method of chemical bonds.
By lack of electrical charges, molecules can only be distinguished from ions.
Molecules in organic substances are found as components of matter.
