Which statement regarding CAM plants is true? A) They use one cell type to absorb and store CO₂ before utilizing it in the Calvin cycle in another cell type. B) They are more efficient than C₄ plants. C) They absorb CO₂ at night and release it to the Calvin cycle during the day. D) They store CO₂ in 3-phosphoglycerate before releasing it to the Calvin cycle.

Question

Quizplus · Accepted Answer

CAM plants (Crassulacean Acid Metabolism) absorb carbon dioxide at night and store it as an organic acid (mainly malic acid) in their vacuoles. During the day, they release the stored carbon dioxide to the Calvin cycle, allowing them to perform photosynthesis even when the stomata are closed to prevent water loss during hot and dry weather. This makes CAM plants particularly adapted to arid and semi-arid environments. Option A describes C4 plants, which have a different mechanism for concentrating carbon dioxide in specialized cells called bundle sheath cells. Option B is incorrect as both C3 and C4 plants are capable of higher photosynthetic efficiency than CAM plants. Option D describes the basic process of the Calvin cycle in all photosynthetic organisms, but CAM plants use a different strategy to absorb and store carbon dioxide before it enters this cycle.

Which Statement Regarding CAM Plants Is True