Question

Water’s properties of surface tension, cohesion, and adhesion are central to the ability of transpiration to pull water up from the roots to the leaves through the xylem. Sort each statement into the appropriate bin to indicate if the change described in the statement would increase, decrease, or not affect the pull that transpiration generates in the xylem of a tree.

Answer 1

Answer:

6.) larger diameter of stomatal pores

A) Increased transpiration pull

1.) thicker film of water on surface of mesophyll cells

2.) higher relative humidity in air around leaf

B) decreases transpiration pull

3.) less curvature of water surface on mesophyll cell walls

4.) lower rate of water evaporation from surface of mesophyll cells.

5.) larger air space in leaf interior

C) has no effect on transpirational pull.

Explanation:

• Transpiration primarily occurs through stomatal openings in the leaves. Increasing the diameter or size of these opening would ultimately increase the amount of water escaping from them and therefore, increase the transpiration rate.
• Higher humidity in the air entails the presence of greater number of water vapours in the atmosphere. Since osmotic pressure plays a major role in transpiration, therefore, this decreases the rate of transpiration.