Q. Which of the following is appropriate for mass-flow hypothesis :
(a) Large amount of ions are also absorbed along with the absorption of water
(b) As suction pressure increases, absorption of water increases and along with water, absorption of ion also increases
(c) Transpiration pull is responsible for absorption of ions
(d) All of the above
Solution :
Correct option : D According to mass-flow hypothesis, there is a mass flow of mineral ions into the root along with transpiration current. Actually, transpiration creates a suction pressure or transpiration pull, conveyed from leaf xylem to root hair, which causes absorption of water from the soil passively. A large amount of ions are also absorbed along with the absorption of water. When the rate of transpiration is high, absorption of water increases due to increased suction pressure and along with water, absorption of ions also increases. Hence, all the given options are correct.
Thus the correct answer is option D.
