Question

In plants, due to the presence of carbon monoxides and azides, respiration rate

• A. Increases
• B. Increases due to HMP pathway
• C. Remains as such
• D. Decreases

Answer 1

The correct option is D Decreases

Various chemicals such as carbon monoxide, cyanide and azides have an inhibitory effect on respiration rate, both in plants as well as animals. All of these interfere with last electron carrier which is cytochrome oxidase enzyme. As a result of this, cytochrome c is not able to transfer an electron to final electron acceptor which is oxygen in respiration and thus respiration is inhibited. Thus, both plants and animals die unless capable of anaerobic respiration. In case of plants, this leads to the release of heat and hence is known as thermogenic respiration.

Thus, the correct answer is option D.