What is selective permeability? How does the cell achieve this?

Answer: selective permeability is the property of cell membranes that makes the cell membranes to give some molecules or ions entry into or exit out of the cell while preventing others from entering or exiting the cell.

Selective permeability is achieved by the cell through cell membranes.

Explanation: Selective permeability that property of the cell membrane that allows some molecules and ions entry into the cell or exit out of the cell while preventing others from entering or leaving the cell.

Cells achieve selective permeability through the membranes. Cell membranes are lipid bilayer that cover the cell. The bilayer is made up of two layers of lipids in which the fatty acyl chains of the lipids face each other to form a hydrophobic fluid interior and the phosphate head group face outward. The interior of the lipid bilayer is hydrophobic and nonpolar and does not allow the passage of polar and hydrophilic molecules across the membrane. Thus the membranes select what type of molecules and ions that enter or leave the cell.

This is a property of cellular membranes which allows only certain molecules to enter or exit the cell. It is determined by the size of the molecule, as well as the concentration of the molecules on the inside and outside of the cell depending if it keeps homeostasis or not.