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Organisation of cells plant tissues (view source)
Revision as of 14:13, 31 July 2014
, 14:13, 31 July 2014→Notes for teachers
Parenchyma tissue is composed of loosely packed thin wall cells so that large spaces between cells(intercellular spaces) are found in this tissue. This tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis, and then it is called
Parenchyma tissue is composed of loosely packed thin wall cells so that large spaces between cells(intercellular spaces) are found in this tissue. This tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis, and then it is called
chlorenchyma. In aquatic plants like pistia and lotus, large air cavities are present in parenchyma to give buoyancy to the plants to help them float.Such a parenchyma type is called aerenchyma. The parenchyma of stems and roots also stores nutrients and water.<br>
chlorenchyma. In aquatic plants like pistia and lotus, large air cavities are present in parenchyma to give buoyancy to the plants to help them float.Such a parenchyma type is called aerenchyma. The parenchyma of stems and roots also stores nutrients and water.<br>
COLLENCHYMA TISSUE:<br>
COLLENCHYMA TISSUE:<br>
The flexibility in plants is due to another permanent tissue, collenchyma. It allows easy bending in various parts of a plant (leaf,stem,petiole) without breaking. It also provides mechanical support to plants. We can find this tissue in leaf stalks below the epidermis.The cells of this tissue are living, elongated and irregularly thickened at the corners. There is very little intercellular space.The cell wall is made up of cellulose and pectin.<br>
The flexibility in plants is due to another permanent tissue, collenchyma. It allows easy bending in various parts of a plant (leaf,stem,petiole) without breaking. It also provides mechanical support to plants. We can find this tissue in leaf stalks below the epidermis.The cells of this tissue are living, elongated and irregularly thickened at the corners. There is very little intercellular space.The cell wall is made up of cellulose and pectin.<br>
http://everythingscience.co.za/lifesciences/grade-10/04-plant-and-animal-tissues/images/6d29e2ef912af90a6d0451f417787577.png<br>
http://everythingscience.co.za/lifesciences/grade-10/04-plant-and-animal-tissues/images/6d29e2ef912af90a6d0451f417787577.png<br>
SCLERENCHYMA:<br>
Sclerenchyma is the tissue which makes the plant hard and stiff. We have seen the husk of a coconut. It is made of sclerenchymatous tissue. The cells of this tissue are dead. They are long and narrow as the walls are thickened due to lignin (a chemical substance which acts as cement andhardens them). Often these walls are so thick that there is no internal space inside the cell. This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts. It provides strength to the plant parts.<br>
The cell wall of sclerenchyma cells in plants like jute and hemp contain elongated, thread like thick walled cells called fibres.Since fibres are flexible and elastic they are used in coir industries to make gunny bags and ropes.
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