Question

Carbon dioxide enters the leaves through tiny pores present on the surface of the leaves called
A) Chlorophyll
B) Chloroplast
C) Stomata
D) Epidermis

Answer 1

Carbon dioxide is necessary for photosynthesis in plants. Exchange of gases takes place through the leaf surface.

Complete answer:
To answer this question, we must know the structure of the leaf.
Plants are autotrophs. It means they can prepare their own food by the process of photosynthesis. In this process, they convert carbon dioxide in the presence of sunlight and chlorophyll to food or glucose. The upper surface of the leaf is called the epidermis. This lower epidermis is not smooth. It contains tiny pores called stomata present on the lower surface of the leaf. These are intercellular spaces through which gaseous exchange takes place. The stomata are guarded by a guard cell which regulates the opening and closing of stomata. These guard cells chloroplast which contain a green pigment called chlorophyll. Chlorophyll has the capacity to trap sunlight necessary for the process of photosynthesis. The opening and closing of the guard cells is regulated by the turgor pressure of water. When the turgor pressure increases, the pore opens.

Additional information: Other than exchange of gases, transpiration also occurs through stomata. Transpiration is the process of loss of water in the form of water vapour from the aerial surface of the plants. It helps in keeping the surroundings cool.

Thus, the correct answer is (C). Carbon dioxide enters the leaves through tiny pores present on the surface of the leaves called stomata.

Note: Photosynthesis occurs during the day time. Thu stomata are open mostly throughout the day for supplying the carbon dioxide to the plants. Respiration occurs throughout day and night.