Explain the different types of permanent tissue
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Answer:
Permanent Tissues
Permanent tissues are those tissue which has lost the power of cell division. Cells of ‘permanent tissues’ are matured, assume a definite shape, size and function. On the basis of constituents call, permanent tissues are classified into three types: simple, complex and secretory or special tissues. Permanent tissues are of two types:
Simple tissues and Complex tissues
(i) Simple tissues: This type of tissue is composed of the same type of cells.
These are again of four types:
(a) Parenchyma simple tissues: Cells of parenchyma tissues are live. They are oval, elongated and loosely packed with large inter-cellular space, forming basic packing of tissue and are found throughout the plant body.
Functions of parenchyma:
They provide mechanical support to the plant body.
They store food and nutrients in vacuoles.
Chlorenchyma: Parenchyma with chlorophyll which performs photosynthesis is called as chlorenchyma.
Aerenchyma: In aquatic plants, cells of parenchyma have large air cavities to give buoyancy to the plant and is called aerenchyma.
(b) Collenchyma simple Tissues: Cells of collenchyma are live. They are oval and elongated and tightly packed with no inter-cellular spaces. They are found below epidermis in leaves and stem.
Learn Meristematic and permanent tissue with animated videos. Click on Class 9 Science for details.
Functions of collenchymas tissues:
They provide mechanical support to plant.
They also provide flexibility to plants so that they can bend without breaking.
(c) Sclerenchyma Simple Tissues: Cells of sclerenchyma are dead. They are narrow and elongated. The cell wall in sclerenchyma is composed of lignin which makes it hard. Sclerenchyma is found around vascular bundles, veins of leaves in the hard covering of seeds and nuts. For exampleSclerenchyma tissues are found in the coconut husk.
Functions of sclerenchyma:
They help to makes parts of plant hard and stiff.
Types of Permanent Tissues
Parenchyma – The cells of this tissue are living, with thin cell walls. Cells can be oval or round in shape. ...
Collenchyma – These cells are living cells and have an elongated shape. The corners of the cell wall are thickened. ...
Sclerenchyma – The cells of the sclerenchyma tissue are dead.