What is a permanent tissue? Classify and describe permanent tissue.
Permanent tissues are derived from meristematic tissue when they lose their ability to divide. The cells of permanent tissue have attained permanent shape, size and function by the process called differentiation.
Permanent tissues are classified into following two types
Simple permanent tissue
Complex permanent tissue
Simple permanent tissues
Simple permanent tissues are made up of only one type of cell structurally and functionally similar.
Simple permanent tissues are further classified in two three types as follows.
Also Check-Differentiate between Parenchyma , Collenchyma and Sclerenchyma on the basis of their cell wall.
- Parenchyma cells are living and possesses the power of division.
- These are simple living cells with little specialization and thin cell wall.
- Cells are usually loosely packed with large spaces between them.
- They are food storage tissues
- Parenchyma provides support to plants.
- Collenchyma tissues are living, irregularly thickened at the corners due to deposit of pectin.
- They have very little intercellular space
- Provides Support and elasticity to the plant
- They are dead cells.
- Cells of sclerenchyma are thickened due to Lignin deposition which also acts as cement and hardens them.
- There is no intercellular space between the cells.
- It provides protective covering to the plant, seeds and nuts.
- It gives rigidity flexibility and elasticity to the plant.
Complex permanent tissues
The complex tissue consists of more than one type of cells having a common origin. The cells of Complex permanent tissues co-ordinate to perform common function.
There are two types of complex permanent tissues
- Xylem is a vascular and mechanical tissue.
- It is responsible for the transport of water and Minerals from Roots to other parts of the plant.
- The cells of xylem have thick walls and many of them are dead.
Xylem consists of many types of elements which are as follows
- Transports food from leaves to other parts of the plant.
- All phloem cells are living except phloem fibers.
Phloem is made up of the following five types of elements.
- Sieve tubes
- Sieve cells
- Companion cells
- Phloem fibers
- Phloem parenchyma.