Question

Gaseous exchange and water loss take place in plants through________

• A. Guard cell
• B. Stomata
• C. Mesophyll
• D. Lenticel

Answer 1

The correct option is B Stomata

• A stomata is a pore, found in the epidermis of leaves, stems, and other organs, that is used to control gas exchange. Carbon dioxide, a key reactant in photosynthesis, is present in the atmosphere at a concentration of about 390 ppm. Most plants require the stomata to be open during daytime.
• The air spaces in the leaf are saturated with water vapour, which exits the leaf through the stomata.
• This is known as transpiration. Therefore, plants cannot gain carbon dioxide without simultaneously losing water vapour. Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata.
• Lenticel is one of many raised pores in the stem of a woody plant that allows gas exchange between the atmosphere and the internal tissues.
• Mesophyll is the tissues of a leaf that are located in between the layers of epidermis and carry on photosynthesis, consisting of the palisade layer and the spongy parenchyma.

Therefore, the correct answer is option B.