Question

Choose the correct answers from the alternatives given.
Stomata are usually open

• A. Whenever there is excess water in the soil
• B. At night, when the plant requires a supply of oxygen
• C. During the day, when the plant requires a supply of carbon dioxide
• D. All of the above

Answer 1

Answer: (C)

During the day, when the plant requires a supply of carbon dioxide

Stomata are tiny openings present on the epidermis of the leaves and young stem. These structures help in transpiration as well as uptake of carbon dioxide. The carbon dioxide is utilised in the process of photosynthesis. Since carbon dioxide is not utilised during the night, its concentration increases which inhibit the uptake of the potassium ions and closing of stomata takes place.

Hence,the correct answer is 'During the day, when the plant requires a supply of carbon dioxide'.