Question

Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because: 1. Effective pumping of CO2 into the 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

Answer 1

photosynthesis is the process in which plants makes their own food with the help of co2 water in the presence of sunlit and chlorophyll

Answer 2

Answer:

The most appropriate answer would be 4. The primary fixation of CO2 is mediated via PEP carboxylase.

In C₄ plants, fixation of atmospheric carbon dioxide occurs in mesophyll cells with the help of PEP carboxylase.  

It fixes carbon dioxide with PEP to form oxaloacetate which is a four carbon first stable compound.  

In contrast to RuBisCO, PEP carboxylase has no affinity towards oxygen due to which atmospheric levels of carbon dioxide is less limited in C₄ plants.

Oxaloacetate then converts into malate which is then transported into bundle sheath cells where it is converted back into PEP with a release of carbon dioxide.  

This carbon dioxide then undergoes Calvin cycle.