Photosynthesis Question 53
53. With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?
[2017]
(a) Increasing atmospheric $CO_2$ concentration up to 0.05% can enhance $CO_2$ fixation rate
(b) $C_3$ plants respond to higher temperatures with enhanced photosynthesis while $C_4$ plants have much lower temperature optimum
(c) Tomato is a greenhouse crop which can be grown in $CO_2$ - enriched atmosphere for higher yield
(d) Light saturation for $CO_2$ fixation occurs at 10% of full sunlight
Show Answer
Answer : b
Hints & Solution
(b) In $C_3$ plants photosynthesis decreases at higher temperature due to increased photorespiration. $C_4$ plants have higher temperature optimum because of the presence of enzyme called pyruvate phosphate dikinase, which is sensitive to low temperature.
