- Exam
- NEET
- Year
- 2023
- Subject
- Botany
- Chapter
- Transport in Plants
NEET 2023 · Botany · Transport in Plants
Given below are two statements: Statement I: The forces generated...
Given below are two statements:
Statement I: The forces generated by transpiration can create pressures sufficient to lift a xylem sized column of water over 130 metres high.
Statement II: Transpiration cools leaf surfaces, sometimes 10 to 15 degrees, by evaporative cooling.
In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- AStatement I is incorrect but Statement II is correct.
- BBoth Statement I and Statement II are correct.
- CBoth Statement I and Statement II are incorrect.
- DStatement I is correct but Statement II is incorrect.
Correct answer
B. Both Statement I and Statement II are correct.
Step-by-step solution
As water evaporates through the stomata, during transpiration, since the thin film of water over the cells is continuous, it results in pulling of water, molecule by molecule, into the leaf from the xylem. Along with cohesive (mutual attraction between water molecules) and adhesive (attraction of water molecules to polar surfaces) forces, transpiration pull is sufficient to lift water nearly 130 meters.
Transpiration:
- Cools the leaf surface.
- Creates transpiration pull.
- Supplies water for photosynthesis.