Question

which definition is the best for \semipermeable membrane\? it is a barrier that prevents materials from moving from one side to the other. it is a barrier that allows materials to move freely from one side to the other. it is a barrier with tiny openings that let some, but not all, materials pass through. it is a barrier that helps materials move from one side to the other. when materials diffuse across a membrane, they move from an area of high concentration to an area of low concentration along the concentration gradient.

Explanation:

A semi - permeable membrane has tiny openings. It allows some materials to pass through while preventing others. Diffusion is the movement of materials from an area of high concentration to an area of low concentration.

Answer:

1. It is a barrier with tiny openings that let some, but not all, materials pass through.
2. high; low