Which substance can enter a cell by diffusion

without having to be digested?

(1) water (3) starch

(2) protein (4) fat

Answer;

The substance that can enter a cell by diffusion without having to be digested is water.

Explanation;

Diffusion involves the movement of molecules from a region of high concentration to a region of low concentration, down a concentration gradient.

Water is able to diffuse through the cell membrane without being digested since it has small molecules.

One property of cell membrane is semi-permeability; it selectively allows material to enter or leave the cell. Large molecules such as starch, fat and proteins, can not enter the cell due to their size and will need to be digested to small molecules for the to gain access to the cell.

(1) water because the others are just too complex to be diffused without being digested but water can be diffused as is.