What is stomata: features of structure and functioning

The leaf is the lateral part of the plant, whichperforms the most important functions of air power and gas exchange. The possibility of their implementation is associated with the features of the elements of the structure of the leaf, one of which is the stomata. With their help, the plant breathes and evaporates water. What is stomata, what are the features of their structure and organization, we will tell in detail in our article.

Breathing and photosynthesis of plants

All living organisms, including plants,are capable of breathing. This all known fact is an indispensable condition for their existence. Its essence lies in the absorption of oxygen, the oxidation of organic substances and the release of carbon dioxide. But the planetary significance of plants is in the implementation of the reverse process - photosynthesis. In its course, carbon dioxide is absorbed, and oxygen, necessary for all living things, is released. Plants are able to perform these two processes simultaneously with different intensities, in large part due to the activity of stomata on the surface of the leaf.

stomata of plants are located

Structure of stomata

What is a stomata? This is a kind of pores, located in the integumentary tissue of plants, which is called peel. The stomata are paired cells predominantly bean-shaped. Their walls are unevenly thickened in different places. Between the cells of the stomata is a stomatal slit. Through it, various gaseous substances are released into plant cells and outwards. Binary cells of stomata can change their shape, as a result of which the size of the gap between them can increase or decrease. As a consequence, the intensity of gas exchange in the plant is regulated.

what is a stomata

Features of stomata functioning

If we understand what is a stomata, thenthat's how they act and on what it depends, we still have to find out. The closing cells are capable of changing their shape depending on the amount of water. If there is a lot of this substance in the plant, they swell, increase in size and move away from each other. The stomatal slit, naturally, increases. The gas exchange process becomes more intense. Excess water leaves the gap, evaporates, and the plant does not overheat during the hot season.

Transpiration is also most intense whena condition for raising the air temperature and increasing the strength of the wind. In the opposite case, when moisture is not enough, the mechanism of action of the closing cells is different. They fit tightly to each other, while the stomatal gap simply disappears, which prevents the process of evaporation of water. As a result, the plant does not lose moisture under conditions of its lack.

stomata are located

Location of stomata

As already mentioned, the stomata are structuresliving cover tissue of plants. It is called peel. The stomata of plants are located, in most cases, on the underside of the leaf. This is a kind of protection from direct sunlight. Also, the water reserve in the plant cells is better preserved. But not all leaves are horizontal. For example, they grow vertically in irises. Therefore stomata are distributed on all sides of the leaves.

The situation is different in aquatic plants. The lower part of their leaves can not contain stomata. After all, they are completely immersed in water, and therefore will not be able to carry out their functions. Stem of such plants are on the surface of the leaf blade. The number of them is quite large, since on one square centimeter of the sheet - up to several tens of thousands of such formations.

location of stomata

Plants without stomata

And some plants are devoid of stomata. For example, the leaves of the Elodea are immersed in water completely, so they can not contain them. And even if the stomata were there, the exercise of their function would be simply impossible. The whole point is that water enters the cracks, preventing the gas exchange process.

the value of stomata

Significance of stomata

Stomata are located in the integumentary tissue, so theirthe main function is the metabolism of the body with the environment. One of them is water, the process of evaporation of which is called transpiration. Its implementation is very important in order that plants do not overheat during the hot season, because this can lead to their death. When evaporation is undesirable, the stomata practically cease to transpiration, thereby retaining the necessary moisture.

But gymnosperms have a specialdevice of stomata. They are clogged during the winter with special resin. Therefore, all representatives of this department of plants are evergreen. They do not need to discard the foliage to protect themselves from the loss of excessive moisture in the winter. In contrast to them, all the Angiosperms retain viable and escape only during this period. But their leaves fall, so as not to lose water for the winter. Therefore, the herringbone "in winter and summer in one color."

What is a stomata, how are they arranged andcarry out their functions, we have considered in some detail. However, it should also be said that, apart from transpiration, they also serve as a specialized device for oxygen supply, so that the process of respiration and carbon dioxide intake for photosynthesis is possible. In addition, the stomata can control the intensity of all these processes, which depends on external factors, and is manifested in the ability to adapt all living organisms to rapidly changing environmental conditions.

So, in the cover sheet tissue arespecialized education, which are called stomata. They consist of binary closing cells and a gap between them. Thanks to the activity of this structure, the most important processes of water evaporation, photosynthesis and respiration are carried out in the plant organism.

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