Explain about the types structure and functions
of single permanent tissues.
Answers
Explanation:
Types of Permanent Tissue
Simple Permanent Tissue
These are also known as homogenous tissues. They are made up of a single cell type, usually with the same origin, structure, and function.
Simple permanent tissue is further classified into three types:
Parenchyma
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 very small nucleus.
It is found in all parts of the plant.
The protoplasm is living and dense.
Collenchyma
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.
Sclerenchyma
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.
Complex permanent Tissue
The complex tissues are made up of various types of cells carrying out distinct functions and are of two types:
Xylem
It transports water and nutrients from the roots to the leaves of the plant.
It provides support to the plants.
It is divided into-tracheids, vessels, xylem fiber, and xylem parenchyma.
Phloem
It translocates the prepared organic food from the leaves to different parts of the plant.
It is also known as bast.
It is composed of sieve tubes, companion cells, phloem parenchyma, and phloem fibres.
Special Tissues
They are modified structurally to carry out functions secretory in nature and are of two types:
Laticiferous Tissues
The plant tissues have latex.
They originate from the meristematic tissues and mature with other tissues.
The cells are elongated, thin-walled and multinucleated.
Observed in a large number of families such as Euphorbiaceae, Apocynaceae, Compositate, etc.
Glandular Tissues
They possess various glands, that secrete oil, resins, tannin, mucilage, etc.
The gland is situated on the epidermis.