The plasma membrane is known as the selectively permeable membrane as they allow the movements of some selected particles only. The movement are facilitated diffusion, active transport and passive transport.
Water molecules are polar in nature. They can pass through the plasma membrane from its region of the higher concentration towards its region of the lower concentration. They move directly through the simple diffusion and does not require any protein or energy molecule to pass through them.
If you cross rr and RR you get four offspring with the trait Rr. Since there is one capital letter, they will all exhibit the dominant trait. Hope this helped!
