Chapter 6 Tissue CBSE Notes for Class 9
We all know that living organisms are composed of cells from the prior chapter. But, millions of cells are there in the organisms. As a part of this, cells perform many functions in a group or cluster. Cells that perform similar functions are grouped in the body of organisms.
Tissues
When a group of cells works together to perform a specific function in the body then that cluster of cells is called tissue. Examples of tissue also include muscle, phloem, and blood. A group of cells is present in a tissue that has a similar structure. Both animals and plants contain tissue that can be dead or live cells.
Difference between Animal and Plant tissue
Animal Tissue |
Plant Tissue |
1.Most animals contain living cells because they carry out so many functions and continuously need energy.
2.Animal tissues are generally not rigid. 3.Organs of animals that are made up of tissue are more specialized. |
1.Most of the plants contain dead cells because they are immobile and they need support to stay hard on the ground. 2.Plant tissues are rigid in general.
3.The parts of plants that are made up of tissue are less specialized. |
Plant Tissue
A group of cells that are similar in structure and function in the plant body are known as Plant tissue. There are two types of plant tissue which include meristematic tissue and permanent tissue.
Meristematic tissue in plants
Meristematic tissues are dividing cells and can be found in the plant body. The apical part of the plant generally contains the meristematic types of tissues. The vacuoles of this tissue are absent and the tissue is more active.
Permanent tissue in plants
Permanent tissue is the second type of plant tissue that does not have the ability to divide. A process where meristematic tissue takes permanent size, shape, and function is called Differentiation. Permanent tissue has two types which include simple permanent tissue and complex permanent tissue.
Simple permanent tissue
- The simple permanent tissue is present beneath the epidermis in plants. Parenchyma is an example of this type of tissue. A tissue that is composed of similar types of cells and has the same structure of cells is called simple permanent tissue.
- Simple permanent tissue has large spaces between cells and the tissue helps to store food in plants. Sometimes, they perform the photosynthesis process with the presence of chlorophyll and due to the presence of chlorophyll, it is known as Chlorenchyma.
- Parenchyma contains large air cavities in the aquatic plants and this type of parenchyma is known as Aerenchyma.
- Collenchyma is a permanent tissue with living cells that helps plants by providing flexibility. This type of tissue also gives mechanical support to the plant and helps the stems of climbers and tendrils to bend without any breakage.
- Additionally, sclerenchyma is one of the types of permanent tissue that makes the plant appear hard and stiff. The epidermis is the outermost layer of cells which consists of stomata and guard cells.
Complex permanent tissue
- Tissue is formed from many types of cells and the cells that come together to carry out a specific function are known as complex permanent tissue. The types of complex permanent tissue include xylem and phloem.
- Xylem- This type of tissue contains xylem fibres, vessels, Tracheids, and xylem parenchyma. Transport of minerals and water, storage of food, and support are some functions of the xylem.
- Phloem- Phloem is a formation of five types of cells such as sieve tubes, phloem parenchyma, phloem fibre, sieve cells, and companion cells. The parts of plants get food from the leaves and the phloem is responsible for transporting food materials.
Fig. Complex Tissue Types a) Tracheid, b) Vessel, c) Xylem parenchyma and d) Section of Phloem
Animal Tissue
Organs that contract and relax or show movement while functioning is because of the tissue. Like, while breathing we feel changes in our chest due to muscle cells. In the human body, examples of tissue include blood as well as muscle when it comes to breathing. Furthermore, epithelial tissue, muscular tissue, connective tissue, and nervous tissue are all types of animal tissue.
Epithelial Tissue
Epithelial tissue is useful for the protection of the animal body. It covers the body of most animals and keeps body systems separate with the help of barrier formation. Body components such as lung alveoli, skin, kidney tubules, the linings of the mouth, and blood vessels are composed of epithelial tissue.
Squamous Epithelium
A simple flat type of epithelium that is present where transportation of substance takes place through the selectively permeable surface in the cells of lung alveoli linings and blood vessels is called the Simple Squamous Epithelium. The mouth lining, Oesophagus, and Skin that covers the body are composed of Squamous epithelium. A thin and flat layer of tissue is made up of Squamous epithelium.
Stratified Squamous Epithelium
When epithelial cells of the specific part are arranged in layers, it is called stratified squamous epithelium. This type of tissue mainly forms human skin.
Columnar Epithelium
The lining of the stomach and organs is formed from the columnar epithelium. This type of epithelium is also helpful in secretion and absorption. The formation of the ciliated columnar epithelium takes place when the columnar epithelium shows the presence of cilia. Hence, it is called Ciliated Columnar Epithelium.
Cuboidal Epithelium
The linings of kidney tubules and salivary gland ducts contain a cuboidal type epithelium. Both these linings get mechanical support from this epithelium.
Connective Tissue
It is the connective tissue that connects various parts of the body. Bones, Blood, Ligaments, adipose tissues, areolar tissue and tendons, and cartilages are some examples of connective tissue. Blood contains plasma which is a liquid matrix where WBCs, RBCs, and platelets are suspended. Bone is also included in the connective tissue which mainly supports the body. Therefore, a ligament is an example of this tissue that connects two bones and the muscles of the body are connected to the bones via tendons. On the other hand, cartilage is a type of connective tissue is present in the trachea, larynx, nose, and ear. And, adipose tissue is present below the skin which stores fat in the body.
Muscular Tissue
Muscular tissue is made up of muscle fibres that help the body move. This tissue forms muscles in our body. The bones have attached tissues in our body that show striations, this is known as Striated Muscles. Also, this tissue has unbranched, cylindrical, multinucleate, and long cells. The striated muscles are also known as skeletal muscles. We cannot control the contraction and relaxation of blood vessels and other involuntary movements. Hence, all the involuntary movements in our bodies are the result of smooth muscles. They are also known for involuntary muscles or striated muscles. Then, the contraction and relaxation of the heart are controlled by cardiac muscles which consist of branched, uninucleate, and cylindrical cells.
Nervous Tissue
Nerve cells or neurons are basic components that make the nervous tissue which is responsible for transmitting stimulus very quickly from one place to another around the body. The nerves, spinal cord, and brain are made up of nervous tissue. The structure of neurons includes a nucleus, cytoplasm, axon (A single long part), dendrites, and nerve endings in the cell body.
Frequently Asked Questions on class 9 CBSE notes for Tissues
How can I increase my grades using these ‘Tissue’ chapter notes?
‘Tissue’ chapter of class 9 is an important chapter for the academic examination. You can read these most important topics and revise them before your exams. Also, the practice of diagrams will help you to score maximum marks in the examination.
What is the importance of tissue in the human body?
Tissue is responsible for connecting bones, body movement, response, heart rhythm, and many more in the human body. It is difficult for all humans to live without this tissue. So, they are important to carry out different functions in the body.
What types of tissue are there in animals?
There are four kinds of tissue in animal tissue epithelial tissue, muscular tissue, connective tissue, and nervous tissue.