If you have a question that ” What are the two types of Plant Tissues ? ” or any question related to the two types of plant tissues, then you are at the correct place because we are going to discuss about the classification of plant tissues.
But before discussing that ” What are the two types of Plant Tissues ? “, you should know about what is Plant Tissue.
So lets get started…
What is Plant Tissues ?
According to Byju’s, A tissue is a cluster of cells, that are alike in configuration and work together to attain a specific function. Different types of plant tissues include permanent and meristematic tissues.
Tissues are categorized into the following types :
(A) Simple tissues
(B) Compound tissues
Tissues are present in all multicellular organisms, whether plants or animals.
Lets discuss about Plant Cell…
Two Types of Plant Tissues
In higher plants, the cells and tissues differ very much in their kind, form and origin. Based upon the capacity to divide, the plant tissues have been classified into the following two types :
- Meristematic tissue
- Permanent tissue.
Meristematic Tissue or Meristem
This type of tissue is composed of a group of similar and immature cells. These cells divide to form new cells and help in increasing the length and girth of plant.
The main characteristics of this tissue are:
- The cells are small and thin walled.
- The cells are closely packed without intercellular spaces.
- The cells are isodiametric, i.e., they have identical length, breadth and height.
- The cells may be rounded, oval or polygonal.
- The cells have a large conspicuous and dense cytoplasm.
- Vacuoles are absent or very small.
- The cells keep on dividing and produce new cells.
- New cells, thus produced, are converted into mature permanent cells.
- The meristematic cells are parent cells from which all other types of cells are formed.
This type of tissue is found at all the growing points of a plant, such as tips of roots, stems and branches. It is also present between the bark and the wood of trees where it leads to increase in the thickness of stem.
Functions of different types of Meristematic tissues : The main function of meristematic tissue is to form a number of new cells by repeated divisions.
The following functions are performed by different types of meristematic tissues :
- Apical meristem brings about the elongation of the roots and stems, hence, increases length of the plant. It is called primary growth.
- Lateral meristem helps in increasing the diameter and girth of the plants. It is called secondary growth.
- Intercalary meristem causes increase in the length of an organ.
The permanent cells may be dead or living. Depending upon the structure, the permanent tissues are classified into the following two types:
- Simple permanent tissues.
- Complex permanent tissues.
Simple Permanent Tissues
These tissues are made-up of cells which are structurally and functionally similar. They include protective and supporting tissues.
Protective Tissues These tissues are primarily protective in function and include : (i) epidermis, and (ii) cork or phellem.
Though these tissues are primarily concerned with providing support to the plants, yet they also perform many other functions. These tissues are categorized into three types :
Parenchyma : (Gr. para-beside ; enchyma- in filling) Typically, parenchyma consists of isodiametric living cells which may be oval, rounded or polygonal in shape.
Collenchyma (Gr. kolla-glue) : Collenchyma is made-up of living cells which are usually elongated with thick corners. Intercellular spaces are usually absent in this tissue.
Collenchyma cells may be oval, circular or polygonal in shape. Few chloroplasts are usually present in the cells of collenchyma.
Collenchyma is found in the leaf stalks, below the epidermis of leaves and stems of herbaceous dicotyledonous plants. Collenchyma is absent in the roots, leaves and stems of monocot plants.
Sclerenchyma (Gr. scleros-hard) : According to Britannica, Sclerenchyma is one of the three types of ground, or fundamental, tissue in plants; the other two types are parenchyma (living thin-walled tissue) and collenchyma (living support tissue with irregular walls). Sclerenchyma cells occur in many different shapes and sizes, but two main types occur: fibres and sclereids.
Complex Permanent Tissues
The complex tissue consists of more than one type of cells which work together as a unit. Complex tissue helps in the transportation of organic materials, water and minerals. That is why, it is also known as conducting or vascular tissue.
The common types of complex permanent tissues are :
- Xylem or wood up and down the plants.
- Phloem or bast.
Xylem and phloem together form vascular bundles.
Xylem : Xylem is also known as wood. It is a vascular and mechanical tissue. Xylem cells are thick walled. They are found in the form of tubular passages.
Xylem consists of four types of cells called xylem elements.
The transverse walls between the vessel elements are partially or fully dissolved to form continuous channels or water pipes.
The rings present in the trunk of an old tree are the xylem rings. By counting the number of rings, we can determine the age of a tree.
Phloem : Phloem is a living, conducting or vascular tissue. It contains tubes, like xylem, but it performs no mechanical function. Phloem consists of four elements or cells.
These are : (a) Sieve tubes, (b) Companion cells, (c) Phloem parenchyma, and (d) Phloem fibres.
- What is Plant Tissue ?
- What are the two types of Plant Tissues ?
- Meristematic tissue
- Permanent tissue.
- Simple Permanent Tissue
- Supporting Tissue
- Complex Permanent Tissue
- Phloem etc.