Question

Water is passively absorbed by root when

• A. Soil solution is hypotonic
• B. Soil solution is hypertonic
• C. Transpiration rates are high
• D. Shoot pressure is high

Answer 1

The correct option is A Soil solution is hypotonic

Water naturally flows from its own high concentration to its own low concentration, water always flows from a hypotonic to a hypertonic solution. If soil solution is hypertonic, the plants will have to move water against the concentration gradient, in order to absorb water. If water has to be moved against a concentration gradient, energy in the form of ATP has to be provided as input. This process is called as active transport. Thus, the correct answer is option A.