Question

when the outside temperature increases, plant growth normally ______.
a. decreases because the plant cannot receive moisture fast enough
b. increases if moisture is available
c. increases because humidity always increases with the temperature
d. decreases because plants become too hot

Explanation:

To solve this, we analyze each option:

• Option a: When temperature rises, evaporation increases, so plants may struggle to get enough moisture (transpiration and water uptake issues), leading to decreased growth. This aligns with plant physiology and environmental impacts on growth.
• Option b: Temperature increase doesn't guarantee moisture availability; in fact, higher temp often increases evaporation, reducing moisture. So this is incorrect.
• Option c: Humidity doesn't always increase with temperature. In many cases, warm air can hold more moisture but humidity (relative humidity) can decrease if moisture doesn't increase proportionally. So this is wrong.
• Option d: While high temp can stress plants, the primary issue for growth reduction with temp increase is often moisture availability, not just "plants becoming too hot" in a simplistic sense. So a is more accurate.

Answer:

a. decreases because the plant cannot receive moisture fast enough