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09/18/2016
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09/18/2016

WHAT plant tissue

Sheet - plant organ

In biology, tissue is a collection of cells with the same structure and performing the same function. Animal and plant cells differ from each other.

Fabrics formed by them is also different.


When the plants are moved to a terrestrial lifestylea new stage in their evolution. They began to form organs - parts of plants that perform different functions. Accordingly, functions, and have become specialized cells. So any plant tissue.
The higher level of the evolutionary ladder, occupied by one or another plant, the more differentiated its tissues. The most differentiating different tissue flowering plants.
All plant tissue can be divided into two groups: meristem (educational) and permanent tissue.

meristem

Meristem - is embryonic tissue. Their main task - to supply the plant "building material" for his other tissues in the process of growth. To accomplish this, cells need to share what they are doing throughout the life of the plant. The walls of these young cells are thin, large nucleus and small vacuoles.
There are primary and secondary meristems.
Primary meristem forms the seed embryo, andadult plants retained on the tips of roots and shoots, so that these bodies grow in length. The growth of roots and shoots in thickness, as well as restoration of damaged organs provides secondary meristem - phellogen and cambium.

Permanent tissue

Unlike meristem cells, permanent tissue cells lost their ability to divide or even dead. These fabrics are divided into coating, conductive and basic.
Function coating fabrics - to protect the plant. Of all its forms only the epidermis covering the green stems, leaves and flower parts, formed by living cells with thick walls. Cork covering roots, tubers and stems wintering, consists of dead cells, which are impregnated with fat-like substances. Several layers of cork form a crust covering the lower part of the tree trunks.
The conductive fabric carried water, and the organicminerals in different directions: from the soil in the root, the leaves of other organs. Conductive fabric formed from vessels and sieve cells. Vessels - a hollow cage with dead content, shaped like a tube. Sieve - living cells with sieve partitions. Two types of cells form vascular fiber bundles. They are surrounded by mechanical tissue of long cells with thick walls and dead content. Its purpose - to strengthen the plant organs.
Basic tissue - assimilation and stores. Cells assimilation tissue, forming a green stems and leaves of the flesh, contain chlorophyll. The function of this tissue - gas exchange and photosynthesis.
Thin-walled cells filled with storage tissuesstarch, protein, they are available to the cell vacuole juice. Such tissue forms of the plants, which are often used for food - tubers, fruits, bulbs, roots. And it is contained in the seeds.

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