Question

When $C{O}_2$ conc. in atmosphere is increased rate of photosynthesis in $C_3$ and $C_4$ plant will change as follows __________________.

• A. Increased rate in both $C_3$ and $C_4$
• B. Increased in $C_3$ and no effect in $C_4$
• C. Increased in $C_3$ and decreased in $C_4$
• D. No effect on both $C_3$ and $C_4$

Answer 1

The correct option is A Increased rate in both $C_3$ and $C_4$

Answer is option A i.e. "Increased rate in both C3 and C4"
An increase in the concentration of carbon dioxide increases the rate of photosynthesis. CO2 elevation causes considerably higher root, stem and leaf weight in C3 and C4 plants. Hence as vegetative growth of both C3 and C4 plants increases.