45. Active absorption is affected by

(a)  Osmotic concentration

(b)  Associate tissue structures

(c)   Transpiration

(d)  Sucking capacity of root hair

Ans.  (a)      Active absorption takes place by the activity of root itself, particularly root hairs. A root hair cell functions as an osmotic system. Water is absorbed by the root hair due to osmotic differences between soil water and cell sap.