Question

Why are C4 plants able to photosynthesize with no apparent photorespiration?

• A. They do not participate in the Calvin cycle.
• B. They use PEP carboxylase to initially fix CO2.
• C. They are adapted to cold, wet climates.
• D. They conserve water more efficiently.

Answer 1

The correct option is B

They use PEP carboxylase to initially fix CO2.

C4 plants use a more efficient enzyme than rubisco. This enzyme allows for little to no oxygen fixation and much more carbon fixation (in other words, less photorespiration).