Question

With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?

(a) Increasing atmospheric CO₂ concentration up to 0.05% can enhance CO₂ fixation rate.

(b) C₃ plants respond to higher temperature with enhanced photosynthesis while C₄ plants have much lower temperature optimum.

(c) Tomato is a greenhouse crop which can be grown in CO₂ ­enriched atmosphere for higher yield.

(d) Light saturation for CO₂ fixation occurs at 10% of full sunlight.

Answer 1

Ans : (b) C₃ plants respond to higher temperature with enhanced photosynthesis while C₄ plants have  much lower temperature optimum.

Explanation :

C₃  plants have RuBisCo enzyme which gets activated on higher carbon dioxide concentration.C₄ plants have PEP as major CO₂ acceptor. Photosynthetic activity is mainly affected by enzymes rather than temperatures. High temperature leads to destruction of photosynthetic pigments.