Question

The number of stomatal pores per $c{m^2}$ of leaf surface is in the range of
A. 1000-60,000
B. 10-1000
C. 50,000- 100,000
D. 50- 100

Answer 1

Hint: Stomata is the special type of structure present in the epidermis of tree leaves and needles that helps in the exchange of carbon dioxide and water between plants and the environment.
Stomata are also known as stoma.
It is a tiny pore in a plant leaf surrounded by a pair of guard cells.

Complete answer:
In botany, a stoma is also called a stomate and it is a pore, found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange.
The pore is lined by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening.
The term usually refers to the entire stomatal complex that consists of the paired guard cells and the pore itself which is known as the stomatal aperture.
Air enters the plant through these openings where gaseous diffusion takes place.
It contains carbon dioxide which is used in photosynthesis and oxygen which is used in respiration.
Oxygen produced as a by-product in photosynthesis diffuses out in the atmosphere through the same openings.
Also, water vapor diffuses through the stomata into the atmosphere in a process called transpiration.
The size of the stomatal pores ranges from 3-12 $\mu m$ in width and 10-14 $\mu m$ in length.
The number of such stomatal tiny pores varies from 1000 - 60,000 per $c{m^2}$ of leaf surface.
The total area of the pore is approximately 1-2 percent of the total leaf area of the leaf.

So, the correct option is option A. 1000-60,000.

Note:
There is little evidence of the evolution of stomata in the fossil record, but they had appeared in land plants by the middle of the Silurian period.
However, the evolution of stomata must have happened at the same time as the waxy cuticle was evolving – these two traits together constituted a major advantage for early terrestrial plants.