Question

Transpiration cohesion tension theory operates in

• A. Active absorption
• B. Passive absorption
• C. Active and passive absorption
• D. None of the above

Answer 1

Answer: (B)

Passive absorption

According to the most widely accepted theory of Dixon and Jolly for the ascent of sap, is the ascent of sap in plants is a passive physical process, which occurs under the influence of transpiration pull generated due to loss of water from aerial parts. Other than the pull, a continuous column of water is also essential for the rise of water in xylem elements. The continuous column of water is maintained by cohesion forces between water molecules and adhesive forces between water molecules and vascular elements of the plant.

So, the correct answer is option B.