Question

Which of these plants follow the CAM pathway for photosynthesis?

• A. Plants with no leaves
• B. Plants with their leaves reduced to thorns
• C. Plants with sunken stomata
• D. Plants with flattened stems

Answer 1

Answer: (C)

Many desert plants have a thick cuticle on their leaf surfaces and have their stomata arranged in deep pits (sunken) to minimise water loss through transpiration. They also have a special photosynthetic pathway (CAM) that enables their stomata to remain closed during day time. Some desert plants like Opuntia, have no leaves - they are reduced to spines- and the photosynthetic function is taken over by the flattened stems.