Suppose Euphorbia and Maize are grown in the tropical area.
a. Which one of them do you think will be able to survive under such conditions?
b. Which one of them is more efficient in terms of photosynthetic activity?
c. What difference do you think are there in their leaf anatomy?
a) Euphorbia is a CAM plant. It fixes CO2 during night and uses it in daytime. It will be able to survive in hot tropical climate. Maize is a tropical plant. It undergoes C4 cycle and can easily survive in hot climate.
b) Maize being a C4 plant is more efficient in terms of photosynthetic activity C4 plants have low CO2 compensation point (0-10 ppm) and rate of carbon assimilation is rapid. Rate of photorespiration is negligible. C4 plants can perform photosynthesis even when the stomata are closed.
c) Euphorbia has large sized succulent cells and stomata having reniform guard cells closed during the day. Maize plant leaves have kranz anatomy. Stomata possess dumbbell shaped guard cells. The stomata remain open during the day.