3. That the cell membrane is selectively permeable can be best deduced by

(a)  The entry of water from root hair

(b)  The entry of mineral salts from the root hair

(c)   Both together

(d)  The rise of sap in plants

Ans.  (c)           This type of membranes allow selective passage of solutes along with solvent through them. Many biological membranes such as cell membranes, tonoplast and the membranes surrounding the sub-cellular organelles are selectively permeable.