Question

Point out the differences between Active absorption and Passive absorption.

Answer 1

Active Absorption	Passive Absorption
Active absorption takes place by the activity of root and root hairs.	The pressure for absorption is not developed in roots and hence roots play a passive role.
Transpiration has no effect on active absorption.	Absorption regulated by transpiration.
The root hairs have high DPD as compared to soil solution and therefore water is taken by tension.	The absorption occurs due to tension created in xylem sap by transpiration pull, thus water is sucked in by the tension.
Respiratory energy needed.	Respiratory energy not required.
It involves the symplastic movement of water.	Both symplast and apoplast movement of water involved.