Class 9th Tissues - PDF

TISSUES  Topics to be Covered Tissues Plant Tissues Permanent Tissue Animal Tissues Nervous Tissue  Tissues ‘A group of cells having similar shape and function act together to perform a specific function is known as a tissue.’ Structural organisation in li...

TISSUES  Topics to be Covered Tissues Plant Tissues Permanent Tissue Animal Tissues Nervous Tissue  Tissues ‘A group of cells having similar shape and function act together to perform a specific function is known as a tissue.’ Structural organisation in living organisms: ORGAN CELLS TISSUES ORGANS ORGANISM SYSTEM Q. What is the utility of tissues in multicellular organisms? fibers sclereids  Meristematic Tissue Permanent Tissue They do not have the capacity to They have the capacity to divide. divide Meristematic tissue has cells small Permanent tissue has cells large in size and isodiametric in shape.. in size and their shape varies. Vacuoles are usually absent in Vacuoles are present in living meristematic tissue. cells of permanent tissue. Intercellular spaces are generally absent. Visible intercellular spaces are present. Cell walls are thin. Cell walls can be thin or thick either.  Meristematic Tissue Imp orta nt Basis of Location: These tissues are found at Intercalary Meristem is the tips of stems and Apical roots, and sometimes on found at the base of Meristem leaves. leaves or between They help the roots and nodes on branches. shoots grow longer, Intercalary It helps parts like the making the plant taller. Meristem internode or leaves This kind of growth is grow longer. known as primary growth. It helps the root or stem SAM (Shoot RAM (Root become thicker. Apical Apical This thickening is known as Lateral Meristem meristem) meristem) secondary growth. (Padhaai kara karo vrna issi se pitoge) Q.How do meristematic tissues contribute to the healing of wounds in plants?  Permanent Tissue The permanent tissues are composed of those cells which have lost their capability to divide. They have definite shape, size and thickness. The permanent tissue may be dead or living. The division & differentiation of the cells of meristematic tissues give rise to permanent tissues. In cell differentiation, developing tissue and organs change from simple to more complex forms to become specialized for specific functions. Permanent tissues are classified into two types on the basis of Structure and Composition i.e. Simple Permanent Tissues and Complex Permanent Tissues.  Simple Permanent Complex Permanent Tissue Tissue Parenchyma Collenchyma Sclerenchyma  Parenchyma Parenchyma tissues support plants and store food in roots and stems. They form the basic packing tissue in plants. The cells are simple and not very specialized. These cells have thin walls and are alive. They have large gaps between them because they are loosely packed. Chlorenchyma Tissues Aerenchyma Tissues Parenchyma tissues which contain Parenchyma tissues with large air spaces help chlorophyll and can perform plants float by making them buoyant. photosynthesis.  Collenchyma Collenchyma tissues are found in leaf stalks just below the surface. They provide flexibility, allowing leaves and stems to bend without breaking. These cells are alive, long, and have thick corners. There is very little space between these cells.  Sclerenchyma The hard husk of a coconut is made of Sclerenchyma tissues. These tissues are found in stems, around vascular bundles, in leaf veins, and in the hard coverings of seeds and nuts. Their role is to provide hardness and stiffness. Sclerenchyma cells are dead, long, and narrow with thick walls. The walls are thickened by lignin, making them very strong. There is little to no space between these cells due to their thick walls. Q. How are simple tissues different from complex tissues in plants? XYLEM PHLOEM  Xylem It is also known as wood and is a vascular and mechanical tissue. Thick walled cells are found in the form of tubular passages. Xylem consists of four types of cells called as elements Tracheids, Vessels, xylem parenchyma and xylem sclerenchyma.  VESSELS TRACHEIDS They are advance element They are elongated angular dead (generally found in angiosperms). cells (primitive elements) mainly involved in conduction of water Vessels are cylindrical tube like and minerals in gymnosperms. structures placed one above the other end to end which form a continuous channel for efficient conduction of water. XYLEM PARENCHYMA They are small & thick walled parenchymatous cells subjected for storage of starch (food). XYLEM SCLERENCHYMA (XYLEM FIBRE) They are non-living fibres with thick walls and narrow cavities provide mechanical support. Except xylem parenchyma all other xylem elements are dead. The annual rings present in the trunk of a tree are xylem rings. By counting the number of annual rings, we can determine the age of a tree.  PHLOEM Imp orta nt They also consist of both parenchymatous and sclerenchymatous cells. Phloem consists of four types of element which are Sieve tubes, Companion cells, Phloem fibre and Phloem parenchyma. SIEVE TUBES Sieve tubes are slender tube like structures made up of elongated, thin walled cells placed end to end. The end walls of sieve tube cells are perforated by numerous pores, called as sieve plates. Nucleus of sieve cell degenerates at maturity. However, cytoplasm persists, because of protoplasmic continuation of sieve tube with companion cell through plasmodesmata. Sieve cells possess slime protein or protein which is concerned with growth and repair of sieve cells. COMPANION CELLS Companion cells have dense cytoplasm and prominent nuclei. Sieve cells & companion cells are so called sister cells because they originate from single mother cell. PHLOEM FIBRE They give mechanical support to sieve tubes. PHLOEM PARENCHYMA They store food and help in radial conduction of food.  Imp orta Feature Xylem Phloem nt Conducts organic solutes or food Function Conducts water and minerals materials Mostly unidirectional (from roots to Bidirectional (from leaves to Direction of Conduction apical parts) storage/growing parts or vice versa) Tracheids and vessels (dead Conducting Channels Sieve tubes (living elements) elements) Xylem parenchyma (only living Sieve tubes, companion cells, and Living Elements element) phloem parenchyma Dead Elements Tracheids, vessels, and fibers Phloem fibers Provides mechanical strength to the Does not perform a mechanical Mechanical Support plant function Epidermis Cork Tissue  Epidermis The epidermis protects plants from injury, pathogens, and water loss. In desert plants (xerophytes), the thick cuticle of the epidermis reduces water loss by lowering the rate of transpiration. The epidermis in certain areas also allows for gas exchange during respiration and photosynthesis. In roots, epidermal cells increase the surface area, aiding in better absorption of water and nutrients.  CORK The outer protective coat of a tree is called cork. It is one of the components of tree bark. The tissues of bark become old and the secondary meristem replaces them. Cork is made up of multiple thick layers as a result of this process. Functions of cork cells: It protects the tree from bacterial or fungal Dead infection. It prevents water loss through the bark. Cell wall (suberin) Epithelial Tissue Connective Tissue Muscular Tissue Nervous Tissue  Epithelial Tissue Always grows on some other types of tissue. Cells of epithelium are set very close to each other and the tissue rests on a non-cellular basement membrane. Consists of single layer of cells. Blood vessels are absent and non-nervous in nature. It covers all the organs and lines the cavities of hollow organs like stomach. It is primarily protective in function.  Epithelium tissues are classified as Squamous epithelium, Cubical epithelium, Columnar epithelium and Ciliated epithelium. Squamous Epithelium Stratified Squamous Inner surface of mouth, oesophagus, Epithelium blood vessels, alveoli (lungs) outer layer of skin Cuboidal Epithelium Ciliated Epithelium Trachea, Bronchi ,Fallopian (Tubes), Nasal (Cavity), Bronchioles, Uterus Columnar Epithelium nephron (tubules of kidney), salivary glands inner surface of intestine, alimentary canal  Muscular Tissue Imp orta nt The cells of the connective tissue are widely striated muscle spaced and embedded in an Movements are brought about in our body with the help of muscular tissues. They are long fibre-like cells called muscle smooth muscle fibres. They are capable of contraction or relaxation. Types of Muscular Tissue are Striated cardiac muscle muscles, cardiac muscle fibres and Non- striated muscles. Striated Muscles/ Skeletal muscles They are also called as voluntary muscles because these are under the control of one’s will. Muscle fibres or cells are multinucleated and unbranched. Each fibre is enclosed by thin membrane which is called as sarcolemma. Cytoplasm is called as sarcoplasm. These muscles get tired and need rest. Cardiac Muscle Fibres They are only involuntary muscles. Only found in the walls of heart. Their structure is in between the striated and non-striated muscles. They are uninucleated and branched. Branches are united by intercalated disc. In these muscles rhythmic contraction and relaxation occurs throughout the life. Non-striated Muscles They are involuntary muscles also called as smooth muscles. These muscle fibres are uninucleated and spindle shaped. They are not enclosed by membrane but many fibres are joined together in bundles. Such muscles are found in the walls of stomach, intestine, urinary bladder, bronchi, iris of eye etc. Peristaltic movements in alimentary canal are brought about by smooth muscles.  Imp orta Striated Muscle (Voluntary Non-Striated Muscle (Smooth nt Feature Cardiac Muscle Muscles) Muscles) Voluntary (under the control of Control Involuntary Involuntary one’s will) Walls of stomach, intestine, urinary Location Attached to the skeleton Walls of the heart bladder, bronchi, iris, etc. Multinucleated and unbranched Structure Uninucleated, spindle-shaped fibers Uninucleated and branched fibers fibers Enclosed by a thin membrane called Not enclosed by a membrane, fibers Enclosed by sarcolemma with Membrane sarcolemma joined in bundles intercalated discs Cytoplasm Called sarcoplasm Called sarcoplasm Called sarcoplasm Do not get tired, rhythmic Fatigue Get tired and need rest Do not get tired easily contraction and relaxation occur Intermediate structure between Appearance Striated (striped appearance) Non-striated (smooth appearance) striated and non-striated Responsible for voluntary Controls involuntary movements like Controls rhythmic contraction and Function movements peristalsis relaxation of the heart  Connective Tissue Provides structural framework. Connects body parts. Offers protection against infections. Stores fats. Occupies and fills spaces.  BLOOD Blood is fluid connective tissue. Blood flows and transports gases, digested food, hormones, and waste materials to different parts of the body. Blood provides protection. Plasma It forms 55% part of blood. It consistsof 90-91% of water, 7% of protein (Albumin, fibrinogen, globulin), 0.9% of inorganic salt etc. Corpuscles Forms 45% part of blood. RBCs They are also called as erthyrocytes, containing red coloured respiratory pigment called haemoglobin that helps in transportation of oxygen. WBCs They are also called as ‘Soldiers of the body’. They are irregular, amoeboid, phagocyte cells that protect our body by engulfing bacterial & other foreign particles. They are of five types: Monocytes, Lymphocytes, Basophiles, Neutrophiles, Eosinophils. Blood platelets or thrombocytes They are spindle shaped cells which are involved in clotting of blood. Tendon Vs Ligament Q. Describe the structural differences between tendons and ligaments. How does their structure relate to their function?  Bone Vs Cartilage BONE CARTILAGE Q. What are the key types of cartilage, and where are they found in the human body?  Aerolar Tissue Adipose Tissue It is the most distributed Adipose tissue is made up of many connective tissue in the body. round and oval adipocytes filled with This tissue fills spaces inside fat globules. organs Excess nutrients are stored as fat in this and is found between the skin tissue. & muscles, around blood It helps in temperature regulation. vessels, nerves and in the Adipose tissue is commonly found bone marrow. beneath the skin and around internal organs like the kidneys. Human Nervous Nerves System  Nervous Tissue They are highly specialized tissue due to which the animals are able to perceive and respond to the stimuli. Their functional unit is called as nerve cell or neuron. Structural and functional unit of nervous system. Longest cell in body. Cell body is called cyton which is covered by plasma membrane. Structure of a Neuron Imp orta nt  Parts of a Neuron Part Function Branched structures that collect information from the previous neuron and pass it to the Dendrites cell body. Contains the nucleus and other organelles like mitochondria, endoplasmic reticulum, and Cell Body (Soma) Golgi body. Axon Tube-like structure that carries information from the cell body to the nerve endings. The end of the axon where the nerve signal is transmitted to the next neuron or target Nerve Endings cell. Nucleus contains genetic material of the cell  Feature Plant Tissues Animal Tissues Plants are stationary, so they need Animals move, so they need tissues for Movement strong support. movement and support. Growth Growth is limited to certain regions. Growth occurs all over the body. Two main types: Meristematic (dividing) No such distinction; tissues are more Types and Permanent (non-dividing). specialized. Complex organization into organs and organ Organization Simple organization. systems. Mostly living cells are active and require Living/Dead Cells Mostly dead cells provide strength. maintenance. Examples Xylem, Phloem, Apical meristems. Muscles, Blood, Bone. Q. Describe the structure and functions of the central nervous system (CNS). 1. Fill in the blanks: 1. The________ meristem helps to increase the girth of the stem or root. 2. The process by which cells take up a permanent shape, size, and function is called ________. 3. Collenchyma is a ________ tissue present in plants which provides flexibility. 4. The husk of a coconut is composed of ________ tissue. 5. Two kidney-shaped cells called ________ enclose the stomata. 6. The ________ parenchyma stores food and helps in the sideways conduction of water. 7. Tendon is a connective tissue which connects ________ to bones. 8. Heart muscle cells are cylindrical and ________. 1. Fill in the blanks: lateral meristem helps to increase the girth of the stem or root. 1. The________ 2. The process by which cells take up a permanent shape, size, and function is differentiation called ________. 3. Collenchyma is a complex ________ tissue present in plants which provides flexibility. sclerenchyma tissue. 4. The husk of a coconut is composed of _______________ 5. Two kidney-shaped cells called ____________ guard cells enclose the stomata. 6. The ________ phloem parenchyma stores food and helps in the sideways conduction of water. 7. Tendon is a connective tissue which connects ________ muscles to bones. 8. Heart muscle cells are cylindrical and branched/ ________. uninucleate 2. Which of the following tissues has dead cells? (a) Parenchyma (b) Sclerenchyma (c) Collenchyma (d) Epithelial tissue 3. Girth of stem increases due to (a) Apical meristem (b) Lateral meristem (c) Intercalary meristem (d) Vertical meristem 4. Name the following. (a) What is the lining of blood vessels made up of? (b) What is the lining of small intestine made up of? (c) What is the lining of kidney tubules made up of? (d) Where are the epithelial cells with cilia found? 4. Name the following. (a) What is the lining of blood vessels made up of? Squamous epithelium (b) What is the lining of small intestine made up of? Columnar Epithelium (c) What is the lining of kidney tubules made up of? Cuboidal epithelium. (d) Where are the epithelial cells with cilia found? Respiratory tract 5. Give reasons for (a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole. (b) Intercellular spaces are absent in sclerenchymatous tissues. 5. Give reasons for (a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole. Meristematic cells have a prominent nucleus and dense cytoplasm because they are metabolically highly active and are in continuous state of division. Meristematic cells lack vacuole because they do not store food material, waste material, sap, etc. (b) Intercellular spaces are absent in sclerenchymatous tissues. Intercellular spaces are absent in sclerenchymatous tissues because they have a cementing substance (known as lignin) around their cell membrane which makes them stiff and hard. “ Don't Just Stand There, Grow! ”