Photosynthesis in C4 plants is relatively less limited by

Home » Advanced Botany » Photosynthesis » Question

Photosynthesis in C₄ plants is relatively less limited by atmospheric CO₂ levels because of :

1. Effective pumping of CO₂ into bundle sheath cells.
2. Rubisco in C₄ plants has higher affinity for CO₂.
3. Four carbon acids are the primary initial CO₂ fixation products.
4. The primary fixation of CO₂ is mediated via PEP carboxylase.

Correct Option: D

In C₄ plants, initial fixation of carbon dioxide occurs in mesophyll cells. The primary acceptor of CO₂ is phosphoenol pyruvate or PEP. It combines with carbon dioxide in the presence of PEP carboxylase or Pepcase to form oxaloacetate.
C₄ plants are more efficient in picking up CO₂ even when it is found in low concentration because of the high affinity of PEP case.