CLASS 9th TISSUES Best Handwritten Notes made with Shobhit Nirwan We know that all living organisms are composed of cells. Types of Cells ~ - - - I I I I I - - I I I -....---------Multicellular i Unicellular - Y I In multicellular organisms, I In unicellular organisms, a there are millions of cells single cell performs all the I specialised to carry on a I functions. I specific task. Eg- Amoeba I Eg- Human Being I I I - - - I I I I I I I ............. - - - - --- Cells specialised to perform a specific functions are grouped together to form a ‘cluster’. This cluster of cells is called tissue. -- I -................. - I #Kitaabi Definition: A group of cell that are similar in structure and as work I I together to achieve a particular function forms a tissue W - -.................... - 19..--[ NCERT Intext Pg61 ] X - - - i L.P. 1- What is tissue? Ans- A group of cells that are similar in structure and/or work together to achieve a particular function forms a tissue. I I I I I L.P. 2- What is the utility of tissue in multi-cellular organisms. I Ans- 1. They provide defined structure. I 2. They provide mechanical strength. 13. They facilitate division of labor. I - - d - . . . . . . . . . . . . . . . . - I - Plant Tissues Cells specialised to perform a specific functions in plants are plant tissues. Characteristics of plant tissues: 1. Growth in plants occurs only in certain specific regions, this is due to dividing tissues located at the points. 2. These dividing tissues are also called meristematic tissues. 3. When the meristematic tissues takes up a specific role and lose the ability to divide - they form a specific type of permanent tissues. Plant Tissue Meristematic Tissues 6 Permanent Tissues -----------Meristematic Tissues i-......... Meristematic tissues are those tissues in which the cells divide continuously and help in increasing the length and growth of plant. Characteristics: 1. Meristematic tissues may be spherical, oval, polygon or rectangle in shape. 2. They are very active. 3. They have thin cellulose walls. 4. They have very few or no vacuoles 5. They have dense cytoplasm and prominent nuclei. Occurrence: They are growth tissues and found in the growing region. According to the basis of occurrence, they are divided into: d ---------------------7 Intercalary Lateral Apical ----- - - I - I I I I - - - . . . - - - - . I I I . I Found beneath Present at I the bark and in I Situated at ! growing tip of stems and roots. I vascular dicot I I I roots and stem. I Causes organ to I Brings about I increase in I elongation of roots and stems. diameter and Functions I This increases girth, called ! ! ! secondary I height of plant, " called primary I growth. I I growth. I I I I I I I - - - - in - - - - - - - - - - - - I I I i I I I Located at the base of leave and internodes. --- I I - - - I - . . . . . . Produces an increase in the length of organ such as leaves. - I I ! I I i ------------------------- I - - ---! Permanent Tissues S The tissues that are completely grown and have lost the ability to divide are known as permanent tissues. This permanent shape, size and function is attained by the process called differentiation. Permanent Tissues I I Simple Permanent Tissue I I Complex Permanent Tissue I Parenchyma Collenchyma Sclerenchyma I I Phloem Xylem Simple Permanent Tissue The tissues that are made of one type of cells and are structurally and functionally similar. A) PARENCHYMA Nature: 1. Most common simple permanent tissue 2. The cells are rounded or isodiametric 3. They are living cells. 4. They are generally loosely arranged, thus have large space between them. 5. The cell wall is thin. Occurrence: 1. Widely distributed in plant bodies such as stems, roots, leaves. 2. Found in soft part of plants, i.e. cortex of roots, ground tissues. Function: 1. These tissues generally stores food. 2. Serves as a packing tissue- to fill the spaces between other tissue. 3. Transport of materials occurs through cells or cells wall of parenchyma cells. 4. It stores waste product of plants. 5. It maintains the shape and firmness of plants due to its turgid cells. B) COLLENCHYMA Nature: 1. Collenchyma tissue also consists of living cells. 2. Intercellular spaces are generally absent. 3. The cells are elongated in shape. 4. They often contain four chloroplasts. Occurrence: 1. Cells are located below the epidermis of dicotyledon stem and petiole. 2. The cells also occur in the midribs of dicot leaves. Function: 1. It provides mechanical support and elasticity. 2. It allows easy bending in various parts of a plant without actually breakng it. 3. When cells of collenchyma contain same chloroplast, they manufacture sugar and starch. (C) SCLERENCHYMA Nature: 1. They are dead cells and are devoid of protoplasm. 2. The cell walls of sclerenchyma are greatly thickened of lignin. 3. The cell of sclerenchyma are closely packed without intercellular spaces. Occurrence: 1. Occurs in abundance either in patches or definite layers. 2. They are found in stems, roots, veins of leaves, hard covering of seeds and nuts. *Husk of coconut is made of sclerenchyma tissue (present in mesocarp of coconut Function: 1. It gives strength, rigidity, flexibility and elasticity to plant body. The transverse section and longitudinal section of sclerenchyma are as shown: ----------------------- - - Protective Tissues: The tissues which provide protection to the plants from loss of water. : There are two types of protective tissues: (A) Epidermis: 1. The entire surface of plants has an outer covering called epidermis covered with cuticle. 2. It is the outermost layer of cells and is usually made of single layer of cells. Function: 1. The main function is to protect the plant from desiccation and infection. 2. It prevents loss of water. I " *Epidermal cells of leaf bear small pores known as stomata- they I are then enclosed by two kidney shaped cells called guard cells. I Stomata are are necessary for exchange of gases with atmosphere. ! I i I I I I I I (B) Cork (or phellem): It is a protective tissue found in the outer bark of woody I 1. plants, particularly in trees with secondary growth. I I 2. It is a dead, water-resistant, and durable tissue. I 3. It contains a waxy substance called Suberin that makes d the tissue impervious to water and gases, providing excellent I protection to plant. 1I - -........ - ! Complex Permanent Tissue Complex permanent tissues are those that consist of more than one type cells having a common origin. These cells coordinate to perform a common function i.e. to transfer water, mineral salts and food material to various parts of plant body. Xylem Phloem (Transport water) (Transport food) - Both are conducting tissues. - They are also called vascular tissues. - Together both constitutes vascular bundle. XYLEM: 1. It consists of tracheids, vessels, xylem parenchyma and xylem fibres. 2. Tracheids and vessels have tubular structure which allows them to transport water vertically. 3. Xylem parenchyma stores food. 4. Xylem fibres are mainly supportive in nature. PHLOEM: 1. Phloem is made up of five type of cells: sieve cells, sieve tubes, companion cells, phloem fibres and the phloem parenchyma. 2. Sieve tubes are tubular cells with perforated walls. 3. Except phloem fibres, other phloem cells are living cells. 4. Phloem transports food from leaves to other parts of the plant. [ NCERT Intext Pg65 ] 14 I L.P. 1: Name types of simple tissues? Ans- Parenchyma, Collenchyma and sclerenchyma. 3. - - . . . . . . . . . . . . - - I I I I I I S I - I L.P. 2: Where is apical meristem found? Ans- They are found at growing tips and roots. I I I I ! L.P. 3: What tissue makes up the husk of coconut? I I I Ans- Husk of coconut is made up of sclerenchyma tissues. I I i L.P. 4: What are the constituents of phloem? Ans- Sieve cells, sieve tube, companion cells, phloem fibres and I phloem parenchyma. I I I - - -............ - - ↓ Epithelial Tissues Squamous Cuboidal Columnar Ciliated Stratified Squamous Muscular Tissues Skeletal Smooth Cardiac Loose Aerolar ....... Animal Tissue !------- I Dense Ligament Adipose Connective Tissues Skeletal Cartilage Bone Blood Fluid Lymph Nervous Tissues Tendon Epithelial Tissue i -- 1. Covering or protective tissues in the animals are epithelial tissues. 2. It covers most organs and also forms a barrier to keep different body system separate. 3. These are tightly packed and form a continuous sheet. 4. Almost no intercellular space. 5. It has single layer of cells and as a result anything entering or leaving the body must cross atleast one layer of epithelium. 6. The permeability of cells of various epithelia plays an important role in regulating the exchange of materials between the body and external environment and also different parts of body. 7. All epithelium is separated from the underlying tissue by an extra cellular fibrous basement membrane. ------------------Basement Membrane: It is a thin, pliable sheet that provides support - - to tissue as well as supply nutrients and blood to epithelial cells. I I " I i i I I !- ! I All epithelial cells are on basement membrane. - - - . . . . . . . . . . . . . - - - - Epithelial Tissue I I I Simple Squamous Epithelium Stratified squamous epithelium Cuboidal epithelium I Columnar (Ciliated) epithelium I Simple Squamous Epithelium Stratified squamous epithelium - Cells are arranged in single layer. - Cells are arranged in multiple layers. - skin - Oesophagus and the lining of mouth. - Prevents wear and tear. - Forms delicate lining Cuboidal Epithelium: Cells are cube-shaped and are placed on a basement membrane. Location: Lining of kidney tubules as well as in the ducts of the salivary glands. Function: It helps in absorption of useful material from urine before is passed out. Ciliated Columnar Epithelium: In this, cell has hair like projection on the outer surface of epithelial tissue which helps in movement of particle. Location: In respiratory tract, in fallopian tube. Function: It helps in movement of particle. Eg: In respiratory tract, the movement of cilia pushes the mucous forward to clear it. Columnar Epithelium: These cells are tall and cylindrical like pillars. Location: Inner lining of the stomach and intestines. Function: It absorbs nutrients from digested food. Muscular Tissue ---I - - 1. It consists of elongated cells also called muscle fibres. 2. It is responsible for movement in body. (A) Skeletal Muscles/ Striated muscles: They are long, cylindrical, unbranched and multinucleate. Location: They are found mostly attached to bones Function: It helps in voluntary muscle movement and locomotion. I I (B) Smooth Muscle The cells are long with pointed ends and Uninucleate Location: Found in iris of eye, uterus, digestive Tract and other internal organs. Function: Carry out involuntary movement Eg: Movement of food in elementary canal (C) Cardiac muscle Muscle cells are cylindrical, branched and Uninucleate Location: Found only in the walls of heart Function: Rhythmic contraction and relaxation of cardiac muscle help to pump and distributed the blood to various parts of body. Connective Tissue ----I I Areolar Dense Loose Adipose I I Skeletal Bones Cartilage S Fluid Blood Lymph Tendon Ligament - The cells of connective tissue are loosely spaced and embedded in intercellular matrix. - Matrix can be jelly like fluid, dense or rigid Areolar Connective Tissue It is a type of connective tissue that support and helps to protect organs, muscles and many other tissues. Loose Connective Tissue In this, cells are embedded in loose gel like matrix. Location: - Between skin and muscles. - Around blood vessels and nerves. Function: - It fills space inside the organ. - Support internal organs. - Helps in repair of tissues. Dense Connective Tissue In this, cells are embedded in type-1 Collagen-hard matrix. Tendons - It connects muscle to bones. - Fibrous tissue. - Limited flexibility - Great strength Ligament - It connects bones to bones. - Little matrix is present - Considerable strength Adipose Connective Tissue It is formed from aggregation of fat cells. Location: - Below skin - Between internal organs Function: - Cells of this tissue are filled with fat globules - Fat Reservation. - It act as an insulation - storage of fats also lets it act as an insulator. Skeletal Connective Tissue It forms the endoskeleton of the vertebrate body. 1. Cartilage It has extensive matrix of protein and sugar. Location: Nose tip, Ear pinnae Function: Support and flexibility to body parts. 2. Bones Characteristic - It is a strong and non-flexible tissue. - It is embedded in a hard matrix that is composed of calcium and phosphorus compounds. Function - It forms the framework that supports the body. - It also anchors the muscles and supports the main organs of body. Fluid Connective Tissue It makes connectivity in the body (i.e. present in whole body) Blood Characteristics - Composed of blood cells. - Blood cells move in liquid matrix Blood Plasma. - Blood cells are of three types: RBC, WBC and Platelete Function Blood flows and transports gases, digested food, hormones and waste material to different parts of body. Lymph It is a colourless fluid in which one WBC is present. - - Nervous Tissues i !-- . . . Nervous tissue receives stimulus and transmits it from one part of tissue to other. The cells of this tissue are called Nerve cells or Neurons, these are highly specialised for receiving stimulus and then transmitting it very rapidly from one place to another within body itself. Location: Brain, spinal cord and neurons. -----------------------1. Neurons are the body’s longest cells. - - - I i 2. A single neuron consist of (a) Cell body; (b) Axon and (c) Dendrites I I i (a) Cell body: It has nucleus and cytoplasm (b) Axon: It transmits impulse away from the cell body S i (c) Dendrites: It carry information from their tips towards axon. ↓-------------------- - [ NCERT Intext Pg 3 ] 14 I L.P. 1- Name the tissue responsible for movement in our body. Ans- Muscular tissue and nervous tissue are responsible for movement in our body. 3. - - - . . . . . . . . . . . . - - I I I I I I I I L.P. 2- What does a neuron look like? Ans- - A neuron consists of a cell body with a nucleus and cytoplasm, from which long thin hair like parts arises. I - Each neuron has a single long part called the axon, and many I small, short branched parts called dendrites. I I I I I i I I I I i I I I I I I I I I I I I I I I i I I I I I I I I I 1 I I L.P. 3: Give three features of cardiac muscles. Ans- 1. Heart muscles are cylindrical, branched and uninucleated. 2. They are involuntary muscles, cannot be controlled by us. 3. They are striated muscle fibre. -- - . . . . . . . . I I I I L.P. 4: What are the functions of areolar tissue? Ans- 1. It fills space inside the organs. 2. Supports internal organs. 3. Helps in repair of tissues. - I I I I I . - ---
