Question

Which of the following, when present in higher concentrations in air, retards the rate of photosynthesis? 

• A. \({CO}_2\)
• B. \({N}_2\)
• C. \({NO}_2\)
• D. \({CH}_4\)

Hint:

When considering environmental pollutants, remember that some gases, while essential in small amounts, can become harmful when their concentration in the atmosphere exceeds natural levels.

Answer 1

The Correct Option is C

Among the options provided, nitrogen dioxide (\({NO}_2\)) is known to have a detrimental effect on photosynthesis when present in higher concentrations. \({NO}_2\) can lead to the formation of ozone and other photochemical oxidants that can damage plant tissues, thereby reducing the efficiency of photosynthesis. While \({CO}_2\) generally enhances photosynthesis up to a certain level, excess \({NO}_2\) in the environment negatively impacts plant health and their ability to photosynthesize effectively.