C₄ plants conserve water by ________.
A)shuttling CO₂ from the Calvin cycle to the water-splitting photosystem
B)keeping their stomata closed when the weather is hot and dry
C)growing very deep roots
D)running the Calvin cycle at night

Question

Quizplus · Accepted Answer

C₄ plants keep their stomata closed when the weather is hot and dry to conserve water. This is because opening their stomata (tiny openings on leaves) during hot and dry weather can lead to excessive water loss through transpiration. Instead, these plants use a specialized pathway to capture carbon dioxide at night when the stomata can be safely opened and store it in a 4-carbon compound. During the day, this compound releases CO₂ for use in the Calvin cycle, allowing the plant to keep its stomata closed and reduce water loss.

C₄ Plants Conserve Water by ________