Standard photosynthesis (C3) plants are more susceptible to photorespiration than either C4 or CAM plants. Why do most plants lack the C4 pathway?

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C4 and CAM pathways have an energetic cost that makes them advantageous in only very hot and/or arid environments. While C3 plants are more susceptible to photorespiration, this limitation does not typically pose a serious problem for most plant species. Additionally, rubisco is more efficient in C3 plants when compared to rubisco in C4 and CAM plants. The lack of vacuoles in their cells to store the malate generated from CO₂ taken in during the night is not a relevant factor in determining why most plants lack the C4 pathway.

Standard Photosynthesis (C3) Plants Are More Susceptible to Photorespiration Than