Explain the structure of stomata and write its functions class 10
Answers
Answer:
Explanation:
structure of stomata
Stomata are present in leaf epidermis.
They regulate the process of transpiration and gaseous exchange.
They are enclosed by two bean-shaped guard cells.
The guard cells control the opening and closing of stomata.
Functions of stomata:
The two main functions of stomata are to allow for the uptake of carbon dioxide and to limit the loss of water due to evaporation.
1.The gaseous exchange (CO2 and O2) between the intercellular spaces of plant cell and the outer air takes place through stomata during photosynthesis
2.During respiration, plants receive O2 and release CO2 through stomata.
3.Stomata allow the ingress of carbon dioxide and release of oxygen i.e. gaseous exchange takes place through stomata. These gas molecules are really the source of the carbon atoms used by plants to create sugars, proteins, and other vital materials for life.
4.Stomata help in loss of excess water from the surface of leaves in the form of water vapor in plants. The phenomenon is known as transpiration.
5.In plants, carbon dioxide and oxygen are exchanged through the stomata by diffusion. Diffusion is the movement of a substance from a region of higher concentration to a region of lower concentration.
Structure of stomata-
The epidermis of the young shoot and leaves contains numerous minute pores called stomata. Each stomatal opening is surrounded by two cells known as the guard cells. The guard cells are living and contain chloroplasts. Their inner walls (wall towards opening) are thicker and outer walls thinner. The guard cells are surrounded by subsidiary cells or epidermal cells
Fig. 6.4. Structure of stomata. (A) Stomatal pour is open. (B) Stomatal opening is closed
Function of guard cells: The guard cells regulate the opening and closing of the stomatal pore. The unequal thickening of the outer and the inner layer of the guard cells allow the stomatal pore The guard cells swell when water flows into them causing the stomatal pore to open. Because inflow of water in guard cells causes the stretching and bulging of the walls leads to opening of the pore. When there is outflow of water from guard cells, the outer thin walls come to their original position resulting in closure of stomatal pore.
