Question

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

• A. four carbon acids are the primary initial CO₂ fixation products
• B. the primary fixation of CO₂ is mediated via PEP carboxylase
• C. effective pumping of CO₂ into bundle sheath cells
• D. RUBISCO in C₄ plants has higher affinity for CO₂

Answer 1

The Correct Option is B

Plants like sugarcane and sorghum employ a unique mechanism wherein they convert atmospheric carbon dioxide into oxaloacetic acid, a C₄ compound, through the action of phosphoenol pyruvate carboxylase (PEP carboxylase). These plants are categorized as C₄ plants. In C₄ plants, the primary formation of oxaloacetic acid (OAA) is facilitated by PEP carboxylase, making them less susceptible to limitations imposed by atmospheric CO₂ levels.

So, the correct option is (B): The primary fixation of CO₂ is mediated via PEP carboxylase