Which statement best describes the efficiency of the C4 photosynthetic pathway compared to the Calvin cycle?

The C4 photosynthetic pathway is particularly efficient in utilizing carbon dioxide, especially in conditions such as high temperatures and low atmospheric CO2 concentrations. This pathway allows plants to capture and concentrate CO2 in specialized cells, which minimizes photorespiration, a process that can waste energy by allowing O2 to compete with CO2 in the Calvin cycle.

By effectively trapping CO2 and funneling it into the Calvin cycle, C4 plants can maintain higher rates of photosynthesis under stress conditions where C3 plants might be less effective. This adaptation enables them to optimize CO2 fixation and ultimately produce more glucose without losing carbon to photorespiration, which would happen if CO2 levels were inadequate. This ability to utilize CO2 efficiently is a significant advantage of the C4 pathway in certain environments, making this statement the best description of its efficiency compared to the Calvin cycle.