Tissues Notes Class 9

Question

Revise Tissues Notes Class 9 before exam to score high marks.

Answer 1

In last section, we briefed the fundamental units of life notes. This article deals with tissues notes in science which includes Meristematic tissue and permanent tissues. Further it also include epidermis, cork, parenchyma, sclereids, fibres, xylem and phloem. Tissues notes class 9 follows NCERT curriculum which benefits CBSE students for revision during exams.

Tissues:

• Group of cells in multicellular organisms having similar functions are said to be
• Cells of a tissue have similar origin and structure.
• Tissues provide division of labour in multicellular organisms.
• When compared to unicellular organism any work is done more efficiently in multicellular organisms because different groups of cells are specialized in doing different functions.
• Tissues notes class 9 deals with all topics included in CBSE NCERT curriculum.

There are two Kinds of tissues:

• Plant tissues
• Animal Tissues

Plant Tissues:

• Plant tissues provides plant structural strength so they are called supportive tissues.
• These supportive tissues are dead and thus provides mechanical strength and need less maintenance.

Here we have provided you with CBSE class 9 biology notes. In this section tissues notes class 9 is there.

Classification of plant tissues:

There are mainly two types of plant tissues. They are:

• Meristematic tissue
• Permanent tissue.

Meristematic Tissues:

• These tissues are actively involved in growth in plants.
• Cells present in these tissues divide and reproduce new cells.
• Meristematic tissues have thin-walled completely arranged immature cells.
• They have thin cellulose walls, dense cytoplasm and prominent nuclei.
• There are no inter-cellular spaces.
• Large number of cell organelle are present.
• These are present at root and shoot tips.

Tissues notes class 9 will help you to get better exams in CBSE board exams. 

Functions of Meristematic tissues:

• These tissues act as a parent tissues where all the other tissues originates.
• Also, these participate in providing growth by generating new cells.
• New cell generation heals up the site of injury in plants.
• From tissues notes class 9 you can separate important topics for exam purpose.

Classification of Meristematic tissues:

There are mainly three types of meristematic tissues:

• Apical Meristems
• Lateral Meristems
• Intercalary Meristems

Apical meristems:

• Present in roots and shoots.
• Apical meristems are mainly responsible for primary growth in length.
• Cell division in these tissues provides elongation. 

Lateral Meristems

• Present at lateral side of roots and stems (at cork cambium)
• These are responsible for increment of girth (diameter) of root and stem of plant.
• Lateral meristems are thus involved in Secondary growth.
• It helps in formation of vascular tissues.

Intercalary Meristems

• Present at base of leaves or internodes.
• Apical meristems leaves it behind while providing growth to plants.
• These helps to increase the size of leaves.
• Considered to provide primary growth.

Permanent Tissue:

• The cells which have no more capability to divide forms Permanent tissues.
• These tissues are either dead or living.
• Shape, thickness and other measures are fixed.
• The reproduction, division or differentiation of cells by meristematic tissues leads to formation of permanent tissues.
• If the cell of a meristmatic tissues divide to a certain extent they are fully specialized in doing special function. Learn tissues notes class 9 easily.

Classification of Permanent tissues:

There are mainly two types of permanent tissues. It is important to be studied in tissues notes class 9. They are:

• Simple permanent tissue
• Complex permanent tissue

Simple permanent tissue:

• Structurally or functionally similar types of cells constitutes simple permanent tissues.
• Some layers of cell beneath the epidermis are generally simple permanent tissue.
• Classification of tissues is important in tissues notes class 9.

There are two types of simple permanent tissues:

• Protective tissues
• Supportive tissues

Protective tissues:

• These helps in protecting different layers.
• Protective tissues mainly consists of epidermis and cork.
• Here in tissues notes class 9 is this much. Moreover, you will read in higher section.

Epidermis:

• It is a thick outermost protective layer of some plant organs.
• Single layer of cells constitutes epidermis.
• These have no intercellular spaces and are flattened and elongated.
• Epidermis consists of living cells.
• Small pores in leaves called stomata is present in epidermis.
• The epidermis layer for dry region plants are thicker to prevent excess loss of water.

Function of epidermis:

• It prevents the plant from any external infection.
• Cuticle present in the epidermis prevents water loss from leaves.
• During respiration and photosynthesis, the stomata of leaves help in exchange of gases.
• Transpiration also occurs through stomata.
• Read tissues notes class 9 as revision material.

Cork:

• Cork cells are dead cells having very thick walls.
• They don’t have intercellular spaces.
• When plants become older and increase in girth then cork appear at the periphery of roots and stems.
• Cell walls in cork leaves waxy substance called suberin which makes them impermeable to gases and water.
• Resins and tannins are quietly filled in Cork cells.

Function of cork:

• As a protective tissue, it prevents plant from infection, desiccation or mechanical injury.
• Cork does not catch fire easily, so it acts as insulation and shock absorber in plants.
• Nowadays these corks are used to make sports item such as shuttle corks, cricket balls etc.
• CBSE notes are required during exams. Here you can learn tissues notes class 9.

Answer 2

Supportive tissues:

• These tissues play supportive role to plants.
• Further, read tissues notes class 9 for more.

There are three types of supportive tissues:

• Parenchyma
• Collenchyma
• Sclerenchyma

Parenchyma:

• Parenchyma is a fundamental tissue.
• It has thin cell walls irregularly thickened at corners.
• They have no intercellular space.
• Its main role is to store food.
• They are oval or spherical in structures.
• Cell walls consist of pectin and cellulose.
• Chlorophyll is generally not there in parenchyma. Those parenchyma containing chloroplasts are collenchyma and performs photosynthesis.
• CBSE NCERT based notes require you to learn the tissues notes class 9.

Function of parenchyma:

• Parenchyma helps in bending of stems and leaves.
• Parenchyma has a large vacuole for food and water storage.
• Idioblast is the parenchyma which stores excretory product such as gums, resin, oils, tannin etc.
• When it contains chlorophyll then performs photosynthesis.
• If the plant is hydrophytic then a type of parenchyma ‘aerenchyma’ provides buoyancy.

Collenchyma:

• It is made up of living cell and elongated cells.
• It is also called mechanical tissue.
• Collenchyma has thin cell walls but thick at the corners.
• There is no intercellular space.
• They have large vacuoles.
• They have small nucleus.
• These tissues are found below the epidermis in leaves and stem.
• Further in tissues notes class 9 read the specific differences tables.

Function of collenchyma:

• Collenchyma provides flexibility to different parts of the plant.
• It also provides mechanical strength to plants.

Sclerenchyma:

• Sclerenchyma is composed of dead cells.
• It is made up of thick cell walls containing little protoplasm.
• No intercellular space is present.
• These tissues are mainly present at veins of leaves or in hard covering of seeds and nuts.
• Coconut husk is a better example to see the presence of sclerenchyma tissues.

Function of sclerenchyma:

• It makes part of plant hard.
• Also, it provides mechanical strength.
• Learn and revise CBSE tissues notes class 9.

Complex Permanent tissues:

• Complex permanent tissues are made up of different types of cells which work together as a unit.
• These tissues are also responsible for transportation of water, organic materials and minerals.
• Thus, they are also called conducting vascular tissue.
• Together xylem and phloem composes vascular bundles.

Types of Complex Permanent tissues:

There are two types of complex permanent tissues:

1. Xylem
2. Phloem

Xylem:

• It is a vascular mechanical tissue.
• Tabular passages are formed by its walls.
• It consists of tracheids, vessels, xylem parenchyma and xylem fibers.

Tracheids:

• These are long elongated cells with tapered ending.
• Also, they are dead cells.
• They are mainly involved in conduction of water and minerals.

Vessels:

• It has pipe-like structure 
• They are also dead cells having lignified thick cell walls.
• Cell wall does not contain its upper and lower portion.
• These are cylindrical tube like structure.
• They conduct water from these tubes.

Read each topic in detail at tissues notes class 9.

Xylem-Parenchyma:

• They store starch and nutrients.
• They are living cells.

Xylem Sclerenchyma:

• They are dead fibres.
• It has narrow cavity which provides mechanical support.
• Xylem rings are the rings present at the trunk of trees. By this we can determine the age of tree. Further you will read components of phloem in tissues notes class 9.

Phloem:

• It transports prepared food from the leaves to every part of plants.
• It also contains parenchymatous as well as sclerenchymatous
• It doesn’t perform mechanical function.

Components of Phloem:

There are 4 different components of Phloem:

• Sieve tubes
• Companion cells
• Phloem parenchyma
• Phloem fibers

Sieve tubes

• These are tube like structures with perforated walls.
• Also, they have thin cell walls.
• It contains cytoplasm.
• Nucleus and other parts are absent in sieve cells.
• Protein present in sieve cells helps to repair itself.
• These cells carries food and nutrients.
• Here tissues notes class 9 is with all the essential CBSE topics.

Companion cells:

• It has prominent nuclei as well as dense cytoplasm.
• As Sieve and companion cells arise from same mother cells so they are called sister cells.

Phloem parenchyma:

• It acts as food storage to plants.
• It also helps in conduction of food in radial direction.

Phloem fibres:

• Sieve tubes get mechanical support through it.
• They also have a thick cell wall.

Animal Tissues:

• As we know that animal is a complex multicellular organism.
• Blood, muscles are some tissues in animals.

Types of animal Tissues in Class 9 biology tissue notes:

There are four types of animal tissues:

• Epithelial tissues
• Connective tissues
• Muscular tissues
• Nervous tissues

Epithelial tissues:

• Epithelium is the skin which protects our body from external environment.
• It is composed of single layer of cells.
• We can observe epithelium in the inner lining of our mouth, Lining of blood vessels.
• There is no intercellular spaces in the epithelial tissues.
• Fibrous basement membrane separates it from other tissues.
• Learn tissues notes class 9 to score better in exams.

Function of epithelial tissue:

• It protects the organs on which it provides covering.
• Different organs are separated by epithelium.
• It smoothen the passage of food by secreting mucus.
• Also, it acts as selectively permeable membrane for our body and its organs.
• In small intestine the epithelium increase the surface area for absorption.

Types of Epithelial tissues:

There are four different types of epithelial tissues on the basis of shape and function:

• Squamous epithelium
• Cuboidal epithelium
• Columnar epithelium or Glandular epithelium
• Ciliated epithelium

Properties	Squamous Epithelium	Cuboidal Epithelium	Columnar or Glandular Epithelium	Ciliated Epithelium
Cells appearance	Cells are arranged like tiles on the floor.	Vertical section appears as squares but free surface appears hexagonal.	Finger like structures are present at the free ends called microvilli.	These cells may be cuboidal or columnar.
Shape of cells	Surface view are polygonal.	Cube like cells are present.	Tall, cylindrical pillar like structures.	Cuboidal or columnar.
Place of presence	It is present as the nose, blood vessels, lung alveoli and pericardial cavity.	In kidney tubules, salivary glands, sweat glands etc.	At inner surface of stomach, intestine, gall bladder etc.	In lining of trachea, nasal passage, fallopian tube
Functions	/Protects the inner parts of the body from mechanical injury. /It prevents wear and tear in skin. /Checks the entry of germs inside the body. /Provides site for diffusion of gases.	/Organs get mechanical support through it. /Site of secretion of enzymes and gastric juices. /Involves Secretion, absorption and excretion	/Microvilli present which increases the absorption efficiency of intestine. /Gastric juices are secreted by it. /Gives mechanical support to organs.	/Provides movement of particles in a particular direction. /Zygote also moves towards the uterus by the help of ciliated epithelium. /It keeps trachea clean.

Answer 3

Connective tissue:

• Different organs of our body are connected through connective tissues.
• Also, it connects bone to bone and bone to muscles.
• Connective tissue cells, fibers and intercellular medium are present in these tissues
• The cells of these tissues are widely spaced and forms intercellular matrix.
• These matrix may be jelly like, fluid and is dense.
• More likely you can save your previous time by reading tissues notes class 9.

Functions of connective tissues:

• In the organs, connective tissue binds different tissues together.
• The structural framework and mechanical support are provided to different tissues by connective tissues.
• It is also involved in repair of cells, storage of fats etc.

Types of connective tissues:

There are a total of five types of connective tissues:

• Fluid connective tissue
• Areolar connective tissue
• Dense connective tissue
• Adipose connective tissue
• Skeletal tissue

Fluid connective tissue:

There are different fluid connective tissues in our bodies. They are in the tabular form in tissues notes class 9. Take a look at it.

Tissues	Function
Blood and lymph	Blood is a fluid connective tissue which helps in transportation of different materials throughout the body.
Plasma	55% of blood is plasma containing water, protein and inorganic salts.
RBC’s	It contains haemoglobin which helps in transportation of oxygen.
WBC’s	It protects our body from bacteria and viruses. Also it helps in clotting of blood.

Areolar connective tissue:

• These tissues are distributed throughout the body.
• They are present in the spaces present in the organs i.e. between skin and muscles, nerves, bone marrow. So it is also called packing tissue.
• There are two types of fibers contained in it. They are: White and yellow collagen fibers.
• It also paces the process of diffusion of oxygen and nutrients from blood vessels.
• In injury it helps in tissue repair also prevents from foreign toxins.
• The more you indulge the more you will learn in tissues notes class 9.

Dense connective tissues:

• It is termed as fibrous connective tissue.
• It is the primary component of ligaments and tendons.
• Its flexibility is quite less but the strength is high.

Adipose connective tissue:

• These are round and oval shaped.
• It is filled with fat globules.
• It is present near the heart, below the skin, eyeballs and in the brain.
• It insulates our body so that less heat escapes from the body.
• It also acts as the storage of fats.

Skeletal tissues:

• In vertebrates, the endoskeleton forms with the help of skeletal tissues.
• It is hard connective tissue.
• Both cartilages and bones are present in it.

Difference between Bones and cartilages:

The difference between bones and cartilages are given in table as per tissues notes class 9. Take a look at it.

Bones	Cartilages
Bones are hard.	Cartilages are soft.
They are porous.	They are non-porous
It contain blood vessels	It doesn’t contain blood vessels.
The spaces (matrix) contain protein as well as mineral salts.	The matrix are composed of protein.
Larger bones have bone marrow in it.	These are solid structures without having bone marrow.
Bone frames a body.	Cartilage provides flexibility to some body parts.
Bones being hard protects our brain heart etc.	At joints it smoothen body surface.

Muscular tissues:

• Muscle fibers are elongated cells which constitutes to form muscular tissues.
• Muscle tissues are involved in movement of body by contraction and relaxation.
• Read tissues notes class 9 to score better in exams.

Types of muscular tissues:

There are three types of muscular tissues:

• Smooth
• Cardiac
• Striated

Smooth muscles	Cardiac Muscles	Striated Muscles
Involuntary muscles	Involuntary muscles	Voluntary muscles
Uni-nucleated and spindle shaped.	Uni-nucleated and branched.	Muscle fibres are multinucleated and unbranched.
Responsible for perielastic movement in elementary canal.	Rhythmic contraction and relaxation occurs every time.	It gets tird and needs rest.
Present in walls of intestine, urinary bladder, iris, bronchi etc.	They lie between striated and non-striated muscles.	Each fiber enclosed by thin memebrane.

Nervous Tissue:

• Nervous system of an organism is made up of nervous tissue.
• The functional unit in nervous system is called neuron or nerve cells.
• Brain, spinal cord and nerves contains nervous tissue.
• These cells carry impulse over great distance at very high speed.
• A neuron has cell body with a nucleus and cytoplasm.
• From cytoplasm long thin hair- like parts arise called
• Dendrons diversifies with the end temperd as
• It recepts and transmits the information between different parts of the body.
• The dendrites receive impulses and the axon transfers impulses throughout the body.

This article provided you with the tissues notes class 9. You can revise it whenever you want. class 9 biology tissues notes include plants and animal tissues notes. 

Answer 4

Tissue is a group of cells having similar origin, structure& function. Study of tissues is called Histology

2. In unicellular organism (Amoeba) single cell performs all basic functions, whereas in multi-cellular organisms (Plants and Animals) shows division of labor as Plant tissue & Animal tissues.

3. Plant tissues are two types: Meristems & Permanent tissues.

4. Meristems: The Meristems are the tissues having the power of cell division. It is found on those region of the plant which grows.

5. Types of Meristems;

1. The Apical meristems – It is present at the growing tip of the stem and roots and increases the length.

2. The lateral meristems - present at the lateral side of stem anf root (cambium) and increases the girth.

3. The intercalary meristems - present at internodes or base of the leaves and increases the length between the nodes.

( Please refer to Fig. 6.2: location of meristems in plant body , NCERT Book Page- 69).

26. Permanent tissues: Two types such as Simple permanent tissues & Complex permanent tissues.

a) Simple permanent tissues: subdivided as

(i): Parenchyma: Tissues provide the support to plants.They are loosly packed and has large intracellular space.

- Parenchyma with chlorophyll which performs photosynthesis is called as chlorenchyma.

- The parenchyma with large air spaces to give buoyancy is called as aerenchyma .

    Parenchyma also stores food and water.

(ii) Collenchyma: Tissue provides mechanical support, thickened at the corners, have very little intercellular space. It allows easy bending of various parts of a plants without breaking

(iii) Sclerenchyma: Tissue makes the plant hard and stiff, thickened due to lignin and no inter cellular space.

Cells of this tissue are dead and commonly seen in the husk of coconut.

(iv) Guard cells and  Epidermal tissue: The tissue aids in protection and exchange of gases. Guard cells kidney shaped in dicots, dumb bell shaped in monocots to guard the stomata.

The epidermal tissues of roots aid in absorption of water and minerals.

The epidermal tissues in desert plants have a thick waxy coating of Cutin with waterproof quality.

The epidermal tissues form the several layer thick Cork or the Bark of the tree.

Epidermis : Epidermis forms one cell thick outermost layer of various body organs of plants such as leaves, flowers, stems and roots. 

Epidermis is covered outside by cuticle. Cuticle is a water proof layer of waxy substance called as cutin which is  secreted by the epidermal cells. Cuticle is very thick in xerophytes. 

Cells of epidermis of leaves are not continuous at some places due to the presence of small pores called as stomata. Each stomata is guarded by a pair of bean shaped cells called as guard cells. These are the only epidermal cells which possess chloplasts, the rest being colorless.

Functions :

(i) The main function of epidermis is to protect the plant from desiccation and infection.

(ii) Cuticle of epidermis cuts the rate of transpiration and evaporation of water and prevents wilting.

(iii) Stomata in epidermis allow gaseous exchange to occur during photosynthesis respiration.

(iv) Stomata also helps in transpiration.

Cork or phellem : in older roots and stems, tissues at the periphery become cork cells or phellem cells. 

Cork is made up to dead cells with thick walls and do not have any intercellular spaces. The cell walls in cork deposit waxy substance called as suberin. 

The cells of cork become impermeable to water and gasses due to the deposition of suberin. The cork cells are without any protoplasm but are filled with resins or tannins.

Functions :

(i) Cork is protective in function. Cork cells prevent desiccation, infection and mechanical injury.

(ii) Imperviousness, lightness, toughness, compressibility and elasticity make the cork commercially valuable.

(iii) Cork is used for insulation, as shock absorber in linoleum. 

(iv) Cork is used in the making of a variety of sport goods such as cricket balls, table tennis, shuttle cocks, wooden paddles etc.

(Please refer to Fig. 6.3- 6.6, NCERT Book Page-70-73).

b) Complex permanent tissues: The complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function.

They are subdivided as;

Xylem: It consists of tracheids, vessels, xylem parenchyma and xylem fibers. The cells have thick walls,

Function - aids in conduction of water and minerals.

Phloem: It consists of sieve tubes, companion cells, phloem parenchyma, and phloem fibers.

Function - Phloem transports food material to other parts of the plants.

. Animal tissues: Sub divided as epithelial tissue, connective tissue, muscular tissue and nervous tissue.

i. Epithelial tissue: It is a protective covering forming a continuous sheet. Simple epithelium is the one which is extremely thin in one layer, whereas stratified epithelium are arranged in pattern of layers.

Depending on shape and function they are classified as:

a) Squamous epithelium in the lining of mouth and esophagus.

b) Cuboidal epithelium in the lining of kidney tubules and salivary glands.

c) Columnar epithelium in the intestine &Columnar epithelium with cilia in the lining of respiratory tract.

d) Glandular epithelium in the Glands aids in a special function as gland cells, which can secrete at the epithelial surface.

Extra: 

Epithelial tissue lines the surface of a body and forms a protective covering. Epithelium cells are packed tightly together with little intercellular matrix. Epithelial tissue in the body is of two types.

(a) Simple epithelium: It consists of a single layer of cells where cells are in direct contact with the basement membrane. It is further sub-divided into the following types:

(i) Simple squamous epithelium: It consists of a single layer of flat cells with irregular boundaries. It is found in the walls of the blood vessels and in the lining of alveoli.

(ii) Simple cuboidal epithelium: It consists of a single layer of cube-like cells. It is present in regions where secretion and absorption of substances takes place such as the proximal convoluted tubule region of the nephron.

(iii) Simple columnar epithelium: It consists of a single layer of tall, slender cells with their nuclei present at the base of the cells. They may bear micro-villi on the free surfaces. Columnar epithelium forms the lining of the stomach and intestines, and is involved in the function of secretion and absorption.

(iv) Ciliated epithelium: It consists of columnar or cuboidal cells with cilia on their free surfaces. They are present in bronchioles and oviducts from where they direct mucus and eggs in specific directions.

(v) Glandular epithelium:It consists of columnar or cuboidal cells involved in the secretion of substances. Glands are of two types, unicellular glands (goblet cells of the alimentary canal) and multicellular glands (salivary glands). They can be classified as exocrine (ductless glands) and endocrine glands (duct glands) by the method through which they release enzymes.

(b) Compound epithelium: It consists of many layers of cells. It is involved mainly in the function of providing protection and has a limited role in secretion and absorption.

Examples of compound epithelium include the dry surface of the skin or moist inner lining of the buccal cavity, pharynx, pancreatic ducts, and the inner lining of ducts of salivary glands.(Please refer to Fig. 6.9, NCERT Book Page-75).

ii) Connective Tissue: Five Types, such as;

a) Blood: The Blood is a fluid connective tissue. Blood plasma has RBCs (Red Blood Cells) WBCs (White Blood Cells) and platelets. Blood plasma contains proteins, salts and hormones. Blood flows and transports gases, digested food, hormones and waste materials.

b) Bone: The bone is a connective tissue with hard matrix, composed of calcium and phosphorus. A bone is connected by another bone with another connective tissue called ligaments. A bone is connected by muscle with another connective tissue called tendon.

c) Cartilage: The cartilage is a connective tissue with solid matrix composed of proteins and sugars. It is commonly seen in nose, ear, trachea, and larynx.

d) Areolar Connective Tissue: It is found between the skin and muscles, around the blood vessels. It supports internal organs and aids in repair of tissues.

e)Adipose Connective Tissue: It is filled with fat globules for the storage of fat. It acts as insulator. (Please refer to Fig. 6.10, NCERT Book Page-76).

Muscular tissues: They have special contractile proteins responsible for movements. Three types, such as; Striated muscles/skeletal muscles/voluntary muscles :

They are cylindrical, un-branched and multinucleated.They have dark bands and light bands.

Unstriated muscles/smooth muscles/involuntary muscles:

They are commonly called as Smooth muscles, having no striations (dark bands/ light bands are absent). Commonly found alimentary canal, uterus, Iris of an Eye. They are spindle shaped. Involuntary in nature

Cardiac Muscles: They are commonly called as Heart muscles, cylindrical, branched and uni-nucleate. Involuntary in nature.(Please refer to Fig. 6.11, NCERT Book Page-77).

Nervous Tissue: The tissue responds to stimuli. The brain, spinal cord and nerves are composed of nervous tissue or neurons.

A neuron consists of Cell Body, cytoplasm, Nucleus, Dendrite, Axon, nerve ending. The neuron impulse allow us to move our muscles when we want to respond to stimuli.