Question

Lenticels are found in
a. The stem in which secondary growth has taken place
b. The root where secondary growth has occurred
c. The root as well as the stem where secondary growth has occurred
d. None of these.

Answer 1

Hint: A lenticel is a porous tissue. It consists of cells with large intercellular spaces in the perimeter of the secondary growth organs. The bark of woody stems and roots of dicotyledonous flowering plants also possesses intercellular spaces. Its function is to provide a pathway for the direct exchange of gases.

Complete answer:
In plants, diffusion of gases takes place through stomata and lenticel in the bark. These are used to exchange oxygen and carbon dioxide. Lenticels are present in the stem in which secondary growth has taken place. So option A is correct.

Secondary growth occurs in roots due to the presence of cambium. However, it increases the diameter. It does not play any role in the exchange of gases. Lenticels are present in the bark. So option B is incorrect.

Hence, the correct answer is option (A).

Additional information:
Lenticels are formed in the cortical region, therefore the formation of this can be from cambium formed in stellar I.e., cortical region, not vascular cambium. Lenticels are formed in the cortical region, therefore the formation of this can be from cambium formed in extra stelar I.e., cortical region, not vascular cambium

Note: Openings called lenticels are found along woody stems lenticels remain open permanently but stomata don't. Stomata are located in the epidermis. Lenticels are located in the perimeter. These are the result of the secondary growth of plants, it also does not contain any chloroplast while stomata do have chloroplast. Lenticels are the result of secondary growth found in the stem or perimeter of the plant meant for the exchange of gases.