Question

It’s 100 degrees and not a cloud is in sight. What do you expect to happen to the rate of water movement through the plant? Explain why.
A) It will speed up, because the amount of water available to be absorbed by the roots is decreased.

B) It will speed up, because the rate of transpiration will increase.

C) It will stay the same because transpiration rate is naturally regulated.

D) It will slow down, because the cohesion among the water molecules will decrease.

E) It will slow down, because transpiration will decrease due to the lack of a humidity gradient.

Answer 1

Answer: Option B (It will speed up, because the rate of transpiration will increase).

Explanation:

An increased temperature of 100 degrees will speed up the rate of movement of water through plant. Plants through their stomata in the leaves, lenticels in the stem and the cuticle of leaf surface tends to loose more water to that extrinsic environment.

Hence, increase in temperature is directly proportional to increase in transpiration. While decrease in temperature gives rise to low transpiration rate.