Which of the following statements best explains why photosynthesis using C4 or CAM systems may be described as a metabolic compromise? A) Both pathways increase the rate of photosynthesis but also increase the rate of water loss. B) The CAM pathway allows more CO₂ into the plant but also increases the rate of water loss. C) The C4 pathway decreases water loss but also increases the rate of photorespiration. D) Both pathways minimize photorespiration but also expend more ATP in the process of carbon fixation.

Question

Quizplus · Accepted Answer

C4 and CAM photosynthesis pathways are adaptations to reduce photorespiration, a process that decreases the efficiency of photosynthesis. However, these adaptations come at a cost of increased ATP expenditure to concentrate CO2 in specialized cells (in C4 plants) or to fix CO2 at night (in CAM plants), making them metabolic compromises.

Which of the Following Statements Best Explains Why Photosynthesis Using