When levels of CO₂ are experimentally increased in a typical grassland community, C₃ plants generally respond with a greater increase in productivity than C₄ plants. This is because
A) C₃ plants are more efficient in their use of CO₂.
B) C₃ plants are able to obtain the same amount of CO₂ by keeping their stomata open for shorter periods of time.
C) C₄ plants don't use CO₂ as their source of carbon.
D) C₃ plants are more limited by CO₂ availability because they lack mechanisms to prevent transpirational water loss.
E) C₃ plants have special adaptations for CO₂ uptake, such as larger stomata.

Question

Quizplus · Accepted Answer

C₃ plants are more limited by CO₂ availability because they lack mechanisms to prevent transpirational water loss, making them more responsive to increased CO₂ levels compared to C₄ plants, which have adaptations to efficiently fix CO₂ even at lower concentrations.

When Levels of CO₂ Are Experimentally Increased in a Typical