How do natural solutes move across a plasma membrane ? Can the polar nucleus also move across it in the same way ? If not then how are these transported across the membrane ?
Neutral solutes move across the plasma membrane by means of diffusion along the concentration gradient. It moves from higher to lower concentration. No, the polar molecule cannot move across it in the same way.
Polar molecules require a carrier protein of the membrane to facilitate their transport across the membrane. Some ions or molecule are transported across the membrane against their concentration gradient, which is an energy dependent process. It is called active transport. In active transport ATP is utilised.