Understand Tissues and Their Functions with Future Classes: A Guide for CBSE Class 9 Science Students
The CBSE class 9 Science syllabus includes a section on tissues. These notes provide a comprehensive overview of the types of tissues found in plants and animals, as well as the functions of each type. Students can download a PDF version of the notes from the CBSE website and use it as a reference for studying. It is important to understand the structure and function of tissues in order to gain a better understanding of the workings of the human body.
Our CBSE Class 9 Science Chapter Tissue notes are a must-have for students looking to excel in their studies. Our notes are written by Anurag, an expert in the field of Tissue. With our Short Notes PDF download, you can easily review and revise what you have learned in class. We are confident that our notes will help you achieve your academic goals.
Chapter 6 Tissues
Tissues are groups of cells that have a similar structure and act together to perform a specific function.
Are Plants and animals made of the same types of tissues?
Plants
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Stationary or fixed
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Growth in a limited region
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Needless energy to survive
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Most of the tissues are dead
Animals
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They can move
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Growth in every part
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Need more energy to survive
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Most of the tissues are alive
Tissues are two types
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Plant tissues
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Animal tissues
Plant tissues
Plants have two types of tissues Meristematic tissue and permanent Tissue
Meristematic tissue
These are simple living tissues capable of division and formation of new cells. Present in the growing region of plants. Ex. root growing branches etc.
Meristematic Tissues are three types
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Apical meristem
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Intercalary meristem
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Lateral meristem
Apical meristem
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It is present at growing tips of stems and roots
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This tissue leads to the elongation of stems and roots
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This evolved in the primary growth of plants.
Intercalary meristem
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It is present at the internodes
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It is part of apical meristem which is left behind during growth.
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It helps in the longitudinal growth of the plant.
Lateral meristem
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It occurs along the side of the longitudinal axis of the plant
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It gives rise to vascular tissues.
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It causes growth in the girth of the stem and Roots.
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This is responsible for secondary growth.
Permanent tissues
It is composed of those cells which have lost their capability to divide, they have a definite shape, size, and thickness. It may be dead or living.
Permanent tissue are two types
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Simple permanent tissue
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Complex permeant tissue
Simple permanent tissue
These are made up of the same types of cells which are similar in structure and also in function
Simple Permanent tissue includes two types of tissues (a) protective tissues (b) supporting tissues
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Protective tissues are consisted of the Epidermis, Cork or Phellem
Epidermis
It is the outermost single cell layer of plant organs Such as leaves, flowers, roots, etc. It is cover by cutile (waterproof layer).
Stomata
The epidermis has small pores on its surface. These pores are called stomata. These are enclosed by two kidney-shaped cells called guard cells.
Function
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It protects the plant from desiccation and infection.
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Cutile cuts the rate of transpiration and the proportion of water.
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Stomata allow gaseous exchange during photosynthesis
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Stomata also help in transpiration
Cork or phellem
It is made up of dead cells with thick walls and does not have intercellular spaces. Cell wall in cork deposit waxy substance called Subcrin. The cell wall is impermeable. It does not have any protoplasm.
Function
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It prevents plants from infection or mechanical injury
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It is a shock absorber, insulator for plants.
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Provide toughness to plants
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Cork used in making of sports goods like – Cricket ball, table tennis, wooden, paddles, etc.
Supporting Tissues
These tissues are supporting in function. These tissues are three types
​Parenchyma
It thin-walled cell, composed of living cells, oval and spherical in structure. It has large central vacuoles, found in leaves, the pith of stems, and roots.
Function
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Storage foods in large vacuoles
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Provide turgidity to cells
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Photosynthesis
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Wound repair and new growth
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Buoyancy control in aquatic plants
Collenchyma
It forms filler tissues in soft parts of plants present in the cortex, pith primary stems, and roots. It is found epidermis. The cell of this tissue is living, the wall thickened at the corners.
Function
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Provide flexibility to plant pants.
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All provide mechanic’s support
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Filling the vacant place
Sclerenchyma
It is strengthening tissues composed of extremely thick-walled cells made up of lignin. Its cells are dead.
Present in stems, around vascular bundles, in the veins of leaves, and hard covering seeds and nuts.
Function
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Provide strength to plant parts.
Complex Permanent tissues
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It consists of more than one type of cell which works together as a unit.
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It is also known as conducting or vascular tissue.
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It helps in transporting organic material, water, and minerals up and down in the plant.
Complex Permanent tissue is of two types
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Xylem
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Phloem
Xylem
Xylem is the vascular tissue in a plant that transports water and dissolved nutrients upward-from the roots.
Xylem consist of four types of cells
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Tracheid
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Vessels
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Xylem parenchyma
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Xylem sclerenchyma
Tracheid
Elongated angular dead cells are involved in the conduction of water.
Vessels
This one cylindrical tube-like structure is placed one above the other end which forms a channel for the conduction of water.
Xylem parenchyma
Thick cells used for storage of food (Starch)
Xylem sclerenchyma
Non-living fibres with thick walls and narrow cavities provide mechanical support.
Phloem
Phloem is the vascular tissue in the plant which conducts sugars and other metabolic Products upward and downwards from the leaves.
It consists of four types of cells
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Sieve tubes
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Companion cells
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Phloem fibres
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Phloem parenchyma
Sieve tubes
Transport Organic compounds (sugar) made during photosynthesis.
Companion cells
Regulate the activity of Sugar in sieve tubes.
Phloem fibers
Provide mechanical support to sieve tubes.
Phloem parenchyma
It stores food.
Animal Tissues
Animals have four types of tissues
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Epithelial
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Connective
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Muscular
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Nervous
Epithelial Tissue/epithelium Tissue
​It consists of a single layer of cells. Blood vessels are absent. It covers all the organs. The skin, lining of the mouth, lining of blood vessels, kidney tubules, etc. are made up of this tissue.
Epithelium Tissues are classified into four parts
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Squamous
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Cuboidal
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Columnar (Ciliated)
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Stratified Squamous
Squamous Epithelium
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Cells arranged end to end like – tiles on the floor
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It forms the lining of cavities – mouth, oesophagus, nose, alveoli, etc.
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It also forms blood vessels, covering of tongue and skin.
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Epithelial cells are arranged in many layers to prevent wear and tear in the skin.
Cubical Epithelium
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The cell of this tissue is a cube in shape.
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It is found in the kidney, thyroid vesicles, and glands (Salivary glands, sweat glands, etc.)
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It also provides mechanical support
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It forms germinal epithelium– testes and ovaries
Columnar Epithelium
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Pillar-like structure
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It forms the lining of the stomach
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It also forms the small intestine, long intestine, etc.
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It has threads on its surface which help in absorption
Stratified Squamous Epithelium
​It consists of squamous Epithelial arranged in layers present in the uterine, oesophagus, etc.
Connective tissue
The cells of the connective tissue are widely spaced. The basic function is to provide support and connect different organs.
Types of Connective tissue
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Areolar
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Adipose
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Skeletal
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Fluid
Areolar Tissue
This Tissue fills spaces inside Organs and is found between the skin and muscles, around vessels, nerves, and in the bone marrow.
Adipose Tissue
It is found below the heart, brain, and eyeballs, it acts as an insulator and prevents loss of heat from the body.
Skeletal Tissue
​Bone, ligaments, Tendons, Cartilage
Bone
It forms the framework that supports the body. It is non-flexible. Made up of calcium and phosphorus compounds.
Ligaments
Two bones are connected by a ligament. This is very elastic.
Tendons
​It connects muscles to bones. It is fibrous with great strength and limited flexibility
Cartilage
This is elastic, less hard to other bones. It is composed of protein and sugars. Present in nose, ear, and larynx.
Fluid / Vascular Tissue – Types of blood cells
Blood has a fluid matrix called Plasma in which RBC, WBC, Platelets are suspended. It also contains proteins, salts, and hormones.
Red blood cell (RBC)
It contains a red-coloured respiratory pigment called haemoglobin that helps in the transportation of oxygen.
White blood cell (WBC)
​They protect our body from harmful bacteria.
Platelets
It is involved in the clotting of blood.
Muscular Tissue
Movement happens in our body with the help of muscular tissue. They are capable of contraction and relaxation.
Muscular tissue are three types
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Striated muscles
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Smooth muscles
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Cardiac muscles
Striated muscles/ skeletal muscles
These muscles are attached to the skeleton by tendons, Voluntary. These muscles get tired and need rest. The cells of this are multinucleated and unbranched. It contains a special protein called contractile protein, which contracts and relaxes to cause movement.
Smooth muscles
​These muscles involuntary, uninucleate, and spindle-shaped. These are found in the walls of the stomach, intestine, bronchi, iris of the eye, etc.
Cardiac Muscles
These muscles are involuntary. Only found in the wall of the heart. This one uninucleate and branched. In these muscles, rhythmic contraction and relaxation occur throughout life.
Nervous Tissue
Cells of the nervous tissue are highly specialized for being stimulated and then transmitting to stimulus Very rapidly from one place to another. The brain, spinal cord, and nerves are all composed of nervous tissue.