Question

What prevents ions from crossing the plasma membrane via

Answer 1

Simple diffusion is the concept of a substance moving from an area of high concentration to a lower concentration without energy input. Because the plasma membrane is made of lipids which are non-polar, this membrane readily allows non-polar substances to diffuse through easily. If a substance has a charge like that of an ion, it will be difficult for the ion to cross the plasma membrane through simple diffusion. The answer should be B.