Question

select the correct answer. the image shows a magnified view of a leaf’s surface with the stomata visible. what’s the significance of these structures in the process of photosynthesis? a. they’re the sites of maximum photosynthesizing activity because of the concentration of chloroplasts. b. they’re the storage sites of glucose, which is produced during the process of photosynthesis. c. they absorb water vapor from the atmosphere, providing water to the plant for photosynthesis. d. they allow the exchange of gases between cells in the leaf and the external environment. e. they allow light energy to enter the leaf, which is vital for the process of photosynthesis.

Explanation:

Stomata are small pores on leaf surfaces. For photosynthesis, plants need carbon dioxide (CO₂) and release oxygen (O₂). Stomata open to allow gas exchange: CO₂ enters the leaf (for the Calvin cycle in photosynthesis) and O₂ (a by - product) exits. Let's analyze the options:

• Option A: Chloroplasts are the sites of photosynthesis, not stomata. So A is incorrect.
• Option B: Glucose is stored as starch in structures like plastids or in storage organs, not in stomata. So B is incorrect.
• Option C: Roots absorb water, not stomata. Stomata are involved in transpiration (water vapor loss) but not water absorption for photosynthesis. So C is incorrect.
• Option D: Stomata regulate the exchange of gases (CO₂ in, O₂ out) between the leaf's internal cells and the external environment, which is essential for photosynthesis. This matches the function of stomata.
• Option E: Light energy is absorbed by chlorophyll in chloroplasts, not by stomata. Stomata don't play a role in light absorption. So E is incorrect.

Answer:

D. They allow the exchange of gases between cells in the leaf and the external environment.