Question

$C_4$ plants are more efficient in photosynthesis than $C_3$ plants due to

• A. higher leaf area
• B. presence of larger number of chloroplasts in the leaf cells
• C. presence of thin cuticle
• D. lower rate of photorespiration.

Answer 1

Answer: (D)

lower rate of photorespiration.

Answer 2

Plants that utilize the Calvin cycle during the dark phase of photosynthesis are referred to as C3 plants, while those employing the Hatch-Slack pathway during this phase are known as C4 plants. C4 plants have evolved a specialized anatomical structure in their leaves called Kranz anatomy, which aids in reducing or preventing photorespiration. In contrast, C3 plants lack such anatomical adaptations in their leaves, leading to a higher rate of photorespiration, thus decreasing their photosynthetic efficiency.