Simple Permanent Tissues
A tissue is said to be simple when it is made up of only one type of cells. Here ‘one’ type of cells means that they are structurally and functionally ‘similar to one another. Hence simple permanent tissues are composed of cells which are similar in their structures and coordinate with one another to perform a common function or set of functions.
Various simple tissues are found in plants which make up the body of plants. These are
- Parenchyma
- Collenchyma
- Sclerenchyma
(I) Parenchyma: The various features of parenchyma are:
- The cells have an oval or round shape.
- The cell wall is made up of hemicellulose or cellulose.
- The cell is thin-walled.
- The cells have vacuoles and a very small nucleus.
- It is found in all parts of the plant.
- The protoplasm is living and dense.
(II) Collenchyma: Various features of collenchyma are as follows
- Cells are long and thick-walled.
- The cell wall is made up of cellulose and pectin.
- It is the only tissue with the highest refractive index due to the presence of pectin.
- It is found in the epidermis and the vascular bundle of dicot leaf.
- The amount of chloroplast is less in the cells.
- The cells have no intercellular spaces.
(III) Sclerenchyma: It has following features
- These are dead tissues, very hard and rigid in texture.
- Cells are thick-walled with various size and shapes.
- These provide mechanical support and rigidity to the plant.