Question

$C_4$ cycle is

• A. Adjunct to Calvin cycle
• B. Independent cycle
• C. With high RuBP carboxylase efficiency
• D. With PEP carboxylase in bundle sheath cells

Answer 1

Answer: (A)

Adjunct to Calvin cycle

In $C_4$ cycle the Calvin cycle is carried out in bundle sheath cell and is the essential and compulsory part of photosynthesis in every green plant but Hatch and Slack cycle is added to it in which carbon dioxide is trapped in mesophyll cells and lead to the formation of oxaloacetic acid by PEP in presence of PEP carboxylase which increases affinity of carbon dioxide and reduces photorespiration. Thus it is an extra and essential part for Calvin cycle.

So the correct option is 'Adjunct to Calvin cycle'.