Tissues

Xylem

True, totipotency exists in meristematic cells as they have ability of division.

False, cambium has the lateral meristem.

Phloem,

Connective,

True, Intercalary meristem is located at the base of inter-node.

Osteocyte,

True, parenchyma contains isometric cells.

False, Intercellular spcaes generally absent in collencymas.

Chondrocyte,

Blood,

Sclereids form the gritty part of most of ripe fruits and contribute hardness to the seed.

Synapse,

True, cuboidal epithelium forms the lining of ducts of salivary glands.

Food,

False, collagen occurs in white fibre.

True, Vacuoles are absent in meristematic plant cell.

Cutin,

Xylem,

True, cork cells are dead, suberized and compacity arranged.

False, cells of collenchyma has irregularly thickened cell walls.

Cuboidal,

Bones.

True, root hair increase the surface are for absorption in roots.

False, the cells of connective tisseue are loosely spaced.

True, Cardiac muscles undergo rhythmic contraction and relaxation throughout life.

False, tendon binds muscles with bones.

False, the movement of iris of eye controls involuntary muscle.

Epidermis is the plant structure which protects the plant from parasites. The cuticle of epidermis prevents the entry of parasites.

Animals of colder region and fishes of cold water have thicker layer is subcutaneous fat because subcutaneous fat acts as an insulating layer and thus prevents the heat loss from the body if these animals in the cold environment.

(a) (vi); (b) (iii); (c) (v); (d) (iv); (e) (i); (f) (ii).

(a) (iv); (b) (iii); (c) (i); (d) (v); (e) (ii).

Xylem is a complex vescular tissue which is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres. Only xylem parenchyma is the living component.

Phloem is made up of four types of elements: Sieve tubes, companion cells, phloem fibres and the phloem parenchyma. It does not show phloem fibres.

(a) T; (b) T; (c) F; (d) T; (e) F.

Differences between voluntary and involuntary muscles:

(a) Squamous epithelium

(b) Columnar epithelium

(c) Cuboidal epithelium

(d) Respiratory tract

(a) Suberin (b) Sieve tubes (c) Calcium, phosphorus

Epidermis plays a vital role in plants. The cuticle of epidermis helps in reduction of loss of water by evaporation and helps in protecting the plants from pathogens like parasites.

(a) Xylem and phloem (b) Stomata (c) Suberin (d) Sclerenchyma (e) Xylem, phloem, (f) Collenchyma (g) Water, minerals (h) Food, leaves

Water hyacinth has spongy petioles which contain lot of air. Consequently, the plant becomes lighter than water and floats on the surface of water.

Differences between sclerenchyma and paraenchyma tissue:

Epithelial tissue: Epithelial tissue is the simplest animal tissue which composed of one or more layer of cells covering external and internal body organs. There are two types of epithelial tissues:

1. Simple Epithelial tissue: It is composed of single layer of cells.

2. Stratified epithelial tissue: It is composed of many layers of cells.

Depending of the shape of the cells, epithelial tissue is of following types:

(a) Squamous epithelial tissue: The cells of squamous epithelium tissue are extremely thin and flat and form a delicate lining. It is found in the alveoli of lungs and blood vessels and protects the underlying parts from germs, harmful chemicals and injury.

(b) Cuboidal epithelial tissue: It is composed of a single layer of cube-like cells. It is found in kidney tubules and salivary glands. It provides mechanical support to organs and helps in absorption and excretion.

(c) Columnar epithelial tissue: It is composed of a single layer of tall and slender cells. Their nuclei are located at the base. Free surface may have microvilli. It is generaly found in the lining of stomach and intestine and help in secretion and absorption.

(d) Ciliated epithelial tissue: It has finger-like projections called cilia on the outer suface of columnar epithelial. These cilia can move, and their movement pushes the mucus forward to clear it. It is found in respiractory tract.

(e) Glandular epithelial tissue: Some of the columnar or cuboidal epithelial cells get specialised for secretion and are called glandular epithelium. It is found in salivary, gastric, intestine and sweat glands.

(a) Striated muscle

(b) Smooth muscle

(c) Cardiac muscle

(a) Meristemtic tissue is responsible for the growth of plants hence they have actively dividing cells which have prominent nucleus and dense cytoplasm. They do not store food and hence they lack vacuoles.

(b) The cells of this tissue are dead, long and narrow as the walls are thickened due to lignin. These walls are so thick that there is no intercellular space in the tissue.

(c) The grit of pear is formed of stone cells also known as sclereids.

(d) Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. (e) Husk of a coconut is made up of sclerenchymatous fibres which are tightly packed.

A. Characteristics of cork:

(i) Cork is the outer most water proof protective tissue present in older or mature woody stems and roots.

(ii) Cork composed of many layers of dead cells.

(iii) The mature cork cells become dead and filled with tannins, resins and air.

(iv) Cork cells are compactly arranged without intercellular spaces.

(v) Cell have thick walls with the deposition of a water proof material, suberin.

(vi) Lenticles (pores) found on the outer surface of cork which help in aeration of inner tissues.

B. Formation of cork: Cork is formed by a secondary lateral meristem called cork cambium or phellogen. As plants grow older, some cells below the epidermis become meristematic and forms the cork cambium or phellogen. The activity of phellogen produces phellem or cork towards outside and phelloderm or secondary cortex towards inside. The phellem, phellogen and phelloderm together constitute the periderm. It acts as a secondary protective tissue for the stems.

The cells of phellem or cork are normally suberized and impervious to water and air.

C. Functions of cork: Cork performs protective functions in the following ways:

(i) Cork cells being highly suberised and thick-walled protect the inner tissues.

(ii) It protects the inner tissues from the attack of microorganisms and mechanical injury.

(iii) Suberin being water-proof, prevents loss of water.

(iv) Lenticles allow exchange of gases.

(v) Cork is ligh and does not catch fire easily.

(v) Provides insulation from extream hot and cold temperatures.

Xylem and phloem both are conducting or vascular tissues of the plants. They are called as complex tissues because each of them is made of more than one type of cells.

Differences between xylem and phloem:

(a) Differences between Meristematic and Permanent tissues:

(b) The process of loss of ability to divide and taking up a permanent shape, size, structure and function by newly formed cells is called differentiation.

(c) (i) Simple permanent tissues. Parenchyma, collenchymas, sclerenchyma.

(ii) Complex permanent tissue. Xylem, Phloem

Plant tissue in husk of coconut is sclerenchvma fibres.

Reason for stiffness of scrererrchyma is deposition of iig'in in cell walls of its cells.

Sclerenchyrna fibres are thick walled dead cells while parenchyma cells are thin walled living cells.

Parenchyma is the common living component of two complex permanent tissues, xylem and phloem.

Xylem parenchyma store food and helps in later conduction of water.

Phloem parenchyma store food, latex, resins, etc.

Function differences.

The striated muscle cells are long, cylindrical, unbranched and multinucleate.

Parenchyma cells are living and thin walled. They are oval, spherical or polygonal in shape. They have large, intercellular space between the cells.

Nerve impulse travel along the axons and dentrites. Nerve impulses enter a neuron along the dentrites and leave the neuron along the axon. Thus, the correct sequence through which nerve impulse is transmitted is: dendrites, cell body, axon, nerve endings

A coverslip must always be places very gently while mounting in order to avoid the entry of air bubbles.

(a) Bone is a solid, rigid and stong connective tissue. Its matrix is hard. The matrix is made up of organic as well as inorganic (e.g.calcium and phosphorus) components. Calcium and phosphorus make the bone matrix hard. When a bone is dipped in HCI, bone become soft and pliable as its inorganic components get dissolved in the acid. Only organic matter is left.

(b) When a bone is dried, its organic matter get destroyed. Only mineral matter is left.

(a) Ligament is a form of connective tissue which holds two bones together at joints. When ligament get overstreached, it causes sprain.

(b) Heparin is an anticoagulant present in blood that prevent it from clotting. If heparin is absent in blood, blood will be coagulated inside the blood vessels.

(c) Striated muscle contraction causes fatigue due to accumulation of lactic acid.

(a) Apical meristems are the growing parts of the roots and stems and are present at the tips of roots, branches, leaves and shoots. If the apical meristems are damanged or cut, the growth of that part of the plant will stop.

(b) If cork is not formed in older stems or roots, the outer tissues will rupture due to increase in girth which expose the interior to dessication and infection.

(c) Lymph is transported through lymph vessels of the lymphatic system. If lymph is not returned to blood, the blood volume will decrease during passage of materials from tissues to blood and vice versa

(a) A – Transverse section of collenchyma; B - T.S. parenchyma ;

C - T.S. sclerenchyma fibres.

(b) Sclerenchym tissue has heavy deposition of lignin.

(c) Collenchyma tissue provides both mechanical strength and flexibility.

(d) In aquatic plants, large air cavities are present in parenchyma tissue to given buoyancy to the plants to help them float. Such a modified parenchyma is called aerenchyma.

(e) Fibres of Hemp and Jute are obtained from the sclerenchyma fibres.

(a) It is a section of phloem, a complex tissue. Phloem transports food from leaves to the other parts of the plant.

(b) V - Phloem parenchyma; W- Seive tube

(c) X - Sieve plate; Y-Companion cell; Z - Sieve pores.

(d) Sieve tube are associated with companion cells. A mature sieve tube is living but it lacks a nucleus. Companion cells are living and associated with the sieve tubes. Living state of the mature sieve tube cells is regulated by nucleated cornpanion cells. These cells supply the RNA and proteins that keep the sieve tube alive. is associated with companion cells.

(a) Figure A - squamous epithelium;

Figure B - columnar epithelium.

(b) Squamous epithelium is also known as tesselated epithelium or pavement epithelium.

(c) Simple columnar epithelium lines the gastrointestinal tract and epiglottis.

(d) Simple squamous epithelial cells are extremely thin and flat which allows diffusion of substances through it.

(a) cardiac muscle fibres (Fig A) and striated muscle fibre (Fig B).

(b) X – Intercalated disc; Y – Light band; Z – Dark band

(c) Intercalated disc of cardiac muscle acts as an impulse booster

(d) Striated muscles are also known as voluntary muscle as their movement is under control of our will

(a) It is section of a bone.

(b) W-Periosteum; X-Haversian canel; Y-Canaliculus (plural canaliculi); Z-Endosteum.

(c) The chemical composition of material of bone includes (i) Ossein (30-40%), (ii) Mineral matter (60-70%) of calcium and magnesium carbonate and phosphate.

(d) Haversian canal tends to carry nutrients to the interior of the bone.

True, xylem consists of mainly dead elements.

Cardiac muscles are exclusively found in the heart and show rhythmic contraction and relaxation throughout life.

they ; intercellular ; organic substance

1-(d) ; 2- (c) ; 3- (b) ; 4-(a)

(a) Figure A- Squamous epithelium; Figure B – Columnar epithelium

(b) Squamous

(c) Columnar

(d) Squmous epithelium

The cells of connective tissue are fibroblasts, macrophages, plasma cells, mast cells, adipocytes and leukocytes. Fibroblasts are most common cell type of connective tissue.

Xylem is a complex vescular tissue which is in all parts such as root, stem and leaf of the plant. It is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

The cells of this tissue have thick walls and many of them are non-living.

(i) Tracheids: These are long elongated tubular cells. Tracheids cells are dead. These are found in all vascular plants. Its main function is conduction of water and minerals from root to stem.

(ii) Vessels: These are pipe-like structure. Vessels are dead and have lignified cell wall. They also participate conduction of water and minerals.

(iii) Xylem parenchyma: These are simple parenchyma found in the xylem. These are living cells which store food material.

(iv) Xylem fibres: These are dead cells provide mechanical support to the plant.

(i) Areolar connective tissue-Found in the bone marrow.

(ii) Adipose connective tissue- Below the skin

(iii) Tendon- Between skeletal muscle and bone

(iv) Ligament- Joint

(v) Bone-Skeletal framework

(v) Cartilage- Tip of nose, ear

(vii) Blood-Circulatory system

(viii) Lymph- Lymphatic system

Axon is long, branch process of neuron which carries impulses away from cyton.

Adipose tissue is fat storing connective tissue which is found mainly beneath the skin. Blubber of whale and hump of camel are adipose tissue which store fat.

It is composed of a single layer of cube-like cells. It is found in kidney tubules and salivary glands. It provides mechanical support to organs and helps in absorption and excretion.

Cardiac muscle fibres are branched, striated and uninucleate. These muscles are involuntary. These muscles are exclusively present in the heart and show rhythmic contraction and relaxation throughout life.

Simple tissues are made up of only one type of cells. There are three types of simple tissue occur in plants: Parenchyma, collenchyma and sclerenchyma.

The parenchyma is present in soft parts of the plant such as cortex, pith, palisade and some parts of the flower. It is considered as a fundamental or ground tissue.

The collenchyma is found in few layers below the epidermis of plant. It is generally absent in monocot stems and leaves. The cell wall is unevenly thickened.

The cells of this tissue are living, elongated and tightly packed with no inter-cellular space.

The cells of the sclerencyma are dead. They are long, elongated, narrow, thick walled and lignified.

Epithelial tissue cells are tightly packed and form a continuous sheet. They have only a small amount of cementing material between them and almost no intercellular spaces.

Squamous epithelium is also called pavement epithelium as it is made up of single thin layer of flattened cells.

It is composed of a single layer of tall and slender cells. Their nuclei are located at the base. Free surface may have microvilli. It is generaly found in the lining of stomach and intestine and help in secretion and absorption.

Phloem is a complex tissue in the plant which conducts water from leaves to the other parts of the plant.

Tendon is a form of dense connective tissue which connects a muscle with a bone.

Smooth muscles are found in alimentary canal and blood vessels. The movement of food in the alimentary canal or the contraction and relaxation of blood vessels are involuntary movement.

Platelets are not true cells in the blood.

Ligament is a dense connective tissue which connects a bone with bone.

Dense connective tissue is of two types- tenonds and ligaments.

Haversian canals are present in bone.

Cardiac muscle fibre contains intercalated discs.

The meristem which occurs at the growing tips of roots and shoots and increases the length of the stem and root is called apical meristem.

Permanent tissues formed by meristematic tissues take up a specific role and lose the ability to divide further.

Active divisions take place in the cells of cambium. Cambium is a meristematic tissue.

Intercalary meriste is commonly present at the base of the leaves or internodes (on either side of the node). The intercalary meristem increses the internode length, hence the stem elongates.

Sclerenchyma tissue gives mechanical support to young dicotyledonous stem.

Areolar connective tissue is found between the skin and muscles, around blood vessels and nerves and in the bone marrow. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

Husk of a coconut is made up of sclerenchymatous fibres

Each stomata is surrounded by a pair of guard cells. Guard cells regulate the opening and closing of stomata.

White fibres of connective tissue are made up of collagen.

The matrix of bone is made up of proteins and is heavily coated with salts of calcium and phosphorous. These minerals make the bone very tough.

The grith of stem or root increases due to lateral meristem.

Meristematic tissue is a dividing tissue which occur growing regions of a plant.

Apical and intercalary meristems are meristematic tissues which are responsible for the growth of a plant.

These cells are found associated with sieve tubes and connected with it by simple pits. These cells are long, narrow and thin walled. These cells are living and does not have perforated cell wall.

Parenchyma is a type of permanent tissue. It consists of relatively unspecified and thin walled cells. The cells are living.

Tracheids are long elongated tubular cells. Tracheids cells are dead. These are found in all vascular plants. Its main function is conduction of water and minerals from root to stem.

Phleom is composed of four types of elements i.e., sieve tubes, campanion cells, phloem parenchyma and phloem fibers or bast fibers. All types of cells are living except bast fibers.

This is because of intercalary meristem which is present at the base of internodes in sugarcane and result in the elongationof the plant.

Companion cells do not lose their nucleus at maturity.

The cork cells are dead and compactly packed without intercellular spaces. Their cell walls are coated with suberin (a waxy substance) which makes these impermeable to water and gases.

Columnar epithelium is composed of a single layer of tall and slender cells. Their nuclei are located at the base. It is generaly found in the lining of stomach and intestine and help in secretion and absorption.

Epidermis forms the entire outermost layer of the plant. It acts as a protective tissue and protects the plant from excessive heat or cold and attack of parasitic bacteria and fungi. Stomata present on epidermis help in gaseous exchange and transpiration.

Smooth muscles and cardiac muscles are involuntary wheras striated muscles are voluntary.

Cardiac muscles are found in the wall of heart. These muscels rhythemic contract and relaxe throughout the life continuously without fatigue.

Tendon is a form of connective tissue which connects a bone with a muscle. Skeletal muscles are found in our limbs. Hence, when we are running, skeletal muscles contrat and pull the tendon to move the bones.

Voluntary muscles are found in limbs as their movement is under control of our will.

Ligament is a form of connective tissue which connects two bones together at joints.

Tendon is a form of connective tissue which connects a bone with a muscle. Tendons are fibrous tissue with great strength but limited flexibility.

Bone cells are embedded in a hard matrix that is composed of calcium and phosphorus compounds.

Muscular tissue is responsible for movement in our body. The cells of this tissue contain special proteins called contractile proteins, which contract and relax to cause movement.

Areolar connective tissue is found between the skin and muscles, around blood vessels

and nerves and in the bone marrow. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

Adipose tissue is found below the skin and between internal organs. It is also known as fat storing tissue as it store fat.

Cartilage smoothens bone surfaces at joints and is also present in the nose, ear, trachea and larynx.

Tendon is a type of connective tissue. The brain, spinal cord and nerves all are composed of the nervous system.

A neuron or nerve cell is a structural and functional unit of the nervous system. A typical nerve cell consists of cell body or cyton, axon and dendrites.

Solid or semisolid matrix of cartilage containing cartilage cells called chondrocytes.

Desert plants have thick cuticle to prevent loss of water by transpiration.

Xylem vessles are pipe-like structure which help in the side ways conduction of water in the branches. Vessels are dead and have lignified cell wall.

Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

Survival of plants in terrestrial environment has been made possible by the presence of conduting tissue like xylem.

Nail will remain at the same position as the height of tree increases form the top, not from the bottom.

Epithelial tissue cells are tightly packed and form a continuous sheet. They have only a small amount of cementing material between them and almost no intercellular spaces.

Plants and animals posses different types of tissues because-

(i) Plants are stationary or fixed as they don’t move while animlas move around in search of food, mates and shelter.

(ii) The growth in plants is limited to certain regions, while this is not so in animals.

Tissue provide structural strength, mechanical strength and show division of labour.

Differences between plants and animal tisses:

Intercalary meriste is commonly present at the base of the leaves or internodes (on either side of the node). Since the cell of this tissue are very active, they have dense cytoplasm and prominent nucleus. They have thin cell wall and lack vacuoles.

The intercalary meristem increses the internode length, hence the stem elongates.

(a) Apical meristem: It increases the length of the stem and root.

(b) Lateral meristem: The girth of the stem or root increases due to lateral meristem (cambium).

A simple tissue is made up of only one type of cells. There are three types of simple tissues in plants are:

1. Parenchyma

2. Collenchymas

3. Sclerenchyma.

(a) Parenchyma:

(i) Transverse section:

(ii) Longitudinal section:

(b) Collenchyma:

(i) Transverse section:

(ii) Longitudinal section:

(i) It provides flexibility to plants so that they can easily bend without breaking.

(ii) It also provides mechanical support to plants.

Sclerenchyma is a supporting tissue. It is the tissue which make plant hard and stiff.

Location: This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts.

Structure: The cells of this tissue are dead. They are long, elongated, narrow, thick walled and lignified. These consists of fibres and sclereids.

The sclerenchyma fibers are of great economical importance since they constitute the source material for many fabrics, hemp, flex, jute.

Differences between xylem and phloem:

Differences between tracheids and vessels:

Phloem is made up of four types of elements: Sieve tubes, companion cells, phloem fibres and the phloem parenchyma.

(i) Sieve tubes: These are tubular cells with perforated walls. These cells are responsible for transportation of food and nutrients.

(ii) Companion cells: These cells are found associated with sieve tubes and connected with it by simple pits. These cells are long, narrow and thin walled. These cells are living.

(iii) Phloem fibres: They have thick cell wall and they provide mechanical support to plant.

(iv) Pholem parenchyma: These cells are living and often cylindrical in shape.

The transport of food from leaves to other parts of the plant is called translocation

Tracheids and vessels are collectively called tracheary elements. Their function is to carry water and minerals in upward direction from roots to different parts of the plant.

Parenchyma: Parenchyma tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis.

Collenchyma: It provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

Sclerenchyma: It provides strength to the plants and enables them to withstand various strains.

Xylem is a complex vescular tissue which is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

The cells of this tissue have thick walls and many of them are non-living.

Functions of xylem:

(i) The main function of xylem is conduction of water and minerals from root to stem. Tracheids and vessels are conducting element of xylem.

(ii) Xylem parenchyma are living cells which store food material.

(iii) Xylem fibres are dead cells provide mechanical support to the plant.

Functions of phloem:

(i) The main function of phloem is transportation of food and nutrients from leaves to other parts of the plant. Sieve tube is the conducting element of phloem.

(ii) Phloem fibres provide mechanical support to plant.

There are two types of plant tissues:

(a) Meristematic tissue: It is a group of cells which constantly divide and produce cells indefinitely throughout the life of a plant. Meristematic tissue is found in all the growing parts of a plant such as root tip, shoot tip, etc.

According to their positions in the plant body, meristems are divided into three categories:

(i) Apical meristem

(ii) Intercalary meristem

(iii) Lateral meristem

(b) Permanent tissues: : A permanent tissue is a group of cells which temporarily or permanently cease to divide. On the basis of composition, permanent tissues can be simple and complex:

(i) Simple permanent tissue: Three types of simple permanent tissues occurs in plants

(I) Parenchyma (II) Collenchyma (III) Sclerenchyma

(ii) Complex permanent tissue: There are two types

(I) Xylem (II) Phloem

Sieve tubes do not have but have cytoplasm. They are attached and dependent on companion cells which contains dense cytoplasm and a large elongated nucleus.

Functions of epithelial tissue:

(i) Protection: Epithelial tissue protects the underlying parts from germs, harmful chemicals and injury. The skin, which protects the body, is also made of squamous epithelium.

(ii) Absorption: Epithelial lining of intestine absorb digested food.

(iii) Excretion: Epithelial lining of kidneys help in excretion of nitrogenous waste materials.

(iv) Secretion: Epithelial lining of endocrine glands secrete useful substances.

Three types of muscles are:

(a) Striated or skeletal muscles: Present attached to the bones or skeleton of the body, like muscles of face, neck, arms and and legs.

(b) Unstriated muscles: Occurs as sheets in the walls of internal body organs like stomach, alimentary canal and blood vessels.

(c) Cardiac muscles: Present only in the walls of heart.

Nervous tissue- Neuron, dendrite

Connective tissue-Collagen fibres, elastin fibre

Epithelial tissue- Cilia

Osteoblast- It provides shape to the body.

Chondroblast-It provides support and flexibility to the body

Goblet cells-It secrete mucus.

Neuron-It is highly specialised for being stimulated and then transmitting the stimulus very

rapidly from one place to another within the body.

Muscle cell-It is responsible for movement in our body.

(i) A neuron or nerve cell is structural and functional unit of the nervous tissue.

(ii)It consists of cell body which has cytoplasm and a nucleus.

Bone – It forms framework that supports the body.

Cartilage – It smoothens bone surfaces at joints.

Ligament – It joins bone to bone.

(a) Adipose tissue

(b) Simple squamous epithelium

Functions of blood:

(i) Transport oxygen from the lungs to different parts of the body.

(ii) Transport CO₂ from the body tissues to the lungs.

(iii) Transport digested food i.e., glucose, amino acids, etc. from alimentary canal to various parts of the body for energy, growth and repair.

There are four types of tissues in animals:

(a) Striated muscle fibre:

(b) Unstriated muscle fibres:

(c) Cardiac muscle fibres:

1-(d); 2- (b); 3- (e); 4- (a); 5- (c); 6- (g); 7 – (h); 8 – (f);

(A) (a) (iv) ; (B) (d) (i); (C) (b) (iii); (D) (c) (ii); (E) (g) (VII); (F) (e) (VI); (G) (f) (v)

(i) B; (ii) B; (iii) A; (iv) C;

(i)- T; (ii) – A; (iii) – G, (iv) – T;

Simple tissue: There are three types of simple tissues in plants:

(a) Parenchyma: It is a simple, permanent living tissue which is made up of thin-walled cells. The cells of this tissue are oval, elongated, and loosely packed with large intracellular space. Their cell wall is made up of cellulose. Each cell encloses a large central vacuole, cytoplasm and a prominent nucleus.

Location: The parenchyma tissue is present in soft parts of the plant such as cortex, pith, palisade and some parts of the flower.

Functions: Parenchyma tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis.

(b) Collenchyma: It is a type of permanent tissue which is found few layer below the epidermis of leaves and stem. The cells of this tissue are living, elongated and tightly packed with no inter-cellular space. The cells have small nucleus, large vacuoles and thin cell wall but irregularly thickened at the corners.

Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

(c) Sclerenchyma: It is a supporting tissue. It is the tissue which make plant hard and stiff.

Location: This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts.

Structure: The cells of this tissue are dead. They are long, elongated, narrow, thick walled and lignified. These consists of fibres and sclereids.

It provides strength to the plants and enables them to withstand various strains

Meristematic tissue: It is a group of cells which constantly divide and produce cells indefinitely throughout the life of a plant. Meristematic tissue is found in all the growing parts of a plant such as root tip, shoot tip, etc.

On the basis of their locations in the plant body, meristematic tissues are classified into three categories:

(a) Apical meristem

(b) Intercalary meristem

(c) Lateral meristem

Simple tissue: Three types of simple tissues occur in plants:

(a) Parenchyma (b) Collenchyma (c) Sclerenchyma

(a) Parenchyma: It is a simple, permanent living tissue which is made up of thin-walled cells. The cells of this tissue are oval, elongated, and loosely packed with large intracellular space. Their cell wall is made up of cellulose. Each cell encloses a large central vacuole, cytoplasm and a prominent nucleus.

The parenchyma tissue is present in soft parts of the plant such as cortex, pith, palisade and some parts of the flower.

Parenchyma tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis.

(b) Collenchyma: It is a another type of simple permanent tissue which is found few layer below the epidermis of leaves and stem. The cells of this tissue are living, elongated and tightly packed with no inter-cellular space. The cells have small nucleus, large vacuoles and thin cell wall but irregularly thickened at the corners.

Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

(c) Sclerenchyma: It is a supporting tissue. It is the tissue which make plant hard and stiff.

Location: This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts.

Structure: The cells of this tissue are dead. They are long, elongated, narrow, thick walled and lignified. These consists of fibres and sclereids.

It provides strength to the plants and enables them to withstand various strains.

Complex tissue: Complex tissues are made of more than one type of cells. All these cells

coordinate to perform a common function.

There are two types of complex tissues- Xylem and Phloem.

They are both conducting tissues and constitute a vascular bundle.

Xylem: Xylem is a complex vescular tissue which is in all parts such as root, stem and leaf of the plant. It is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

The cells of this tissue have thick walls and many of them are non-living.

(i) Tracheids: These are long elongated tubular cells. Tracheids cells are dead. They are found in all vascular plants. Its main function is conduction of water and minerals from root to stem.

(ii) Vessels: These are pipe-like structure. Vessels are dead and have lignified cell wall. They also participate conduction of water and minerals.

(iii) Xylem parenchyma: These are simple parenchyma found in the xylem. These are living cells which store food material.

(iv) Xylem fibres: These are dead cells which provide mechanical support to the plant.

Phloem: Phloem is a conducting or vascular tissue of the plants. Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and phloem parenchyma.

and the phloem parenchyma.

(i) Sieve tubes: These are tubular cells with perforated walls. These cells are responsible for transportation of food and nutrients.

(ii) Companion cells: These cells are found associated with sieve tubes and connected with it by simple pits. These cells are long, narrow and thin walled. These cells are living.

(iii) Phloem fibres: They have thick cell wall and they provide mechanical support to plant.

(iv) Pholem parenchyma: These cells are living and often cylindrical in shape.

(a) Differences between RBCs and WBCs:

(b) (a) Differences between bone and cartilage:

(c) Differences between blood and lymph:

(d) ) Differences between striated and unstriated muscles:

(e) Differences between tendon and ligament:

(f) Differences between axon and dentrite:

The covering or protective tissues in the animal body are epithelial tissues. Epithelium

covers most organs and cavities within the body. The cells of epithelium tissue are closely packed without intercellular spaces. They cover external body surface and line the various body cavities, internal organs and blood vessels. The lower most layer rests on a non-cellular basement membrane.

Exchange of various materials can occur across the epithelial tissues by diffusion. One side of the cells is in contact with the basement membrane while the other surface of the tissue is in contact with the atmosphere either directly (as in skin) or indirectly (as in lungs and alimentary canal).

Functions of epithelial tissue:

(i) Protection: Epithelial tissue protects the underlying parts from germs, harmful chemicals and injury. The skin, which protects the body, is also made of squamous epithelium.

(ii) Absorption: Epithelial lining of intestine absorb digested food.

(iii) Excretion: Epithelial lining of kidneys help in excretion of nitrogenous waste materials.

(iv) Secretion: Epithelial lining of endocrine glands secrete useful substances.

(i) Areolar connective tissue-Found in the bone marrow.

(ii) Adipose connective tissue- Below the skin

(iii) Tendon- Between skeletal muscle and bone

(iv) Ligament- Joint

(v) Bone-Skeletal framework

(v) Cartilage- Tip of nose, ear

(vii) Blood-Circulatory system

(viii) Lymph- Lymphatic system

Composition of blood: Blood is a fluid connective tissue which circulates in our body. The main components of blood are plasma (55%) and blood corpuscles (45%).

Plasma is straw-coloured fluid which contains 85-90% water and 5-10% other substances like proteins, salts and hormones. There are three types of blood corpuscles:

● RBC (Red blood cells)

● WBC (White blood cells), and

● Platelets

Functions of blood:

(i) Transport oxygen from the lungs to different parts of the body.

(ii) Transport CO₂ from the body tissues to the lungs.

(iii) Transport digested food i.e., glucose, amino acids, etc. from alimentary canal to various parts of the body for energy, growth and repair.

(iv) Transport excretory waste product called urea from the liver to the kidneys for removal as urine.

(v) Plasma regulates water balance in the body.

(vi) Regulates the body temperature.

Muscular tissue: Muscular tissue is a contractile tissue made up of muscles. Muscles consists highly specialised cells called muscle fibres. This tissue is responsible for movement in our body.

Types of muscular tissues:

In human beings, three types of muscles are found:

(a) Striated muscles

(b) Smooth muscles

(c) Cardiac muscles

(a) Striated muscles: Striated muscles are also called voluntary muscles as their movement is under our will. The cells of striated muscles are long, narrow, cylindrical, unbranched with blunt ends. They have multi nucleus.

These muscles are also called skeletal muscles because they are mostly attached to bone and help in body movement. These muscles show alternate light and dark band or striations when stained appropriately. As a result, they are also called striated muscles.

(b) Smooth muscles: Smooth muscles also called as unstriated muscles as they lack transverse striations. They are not under the control of one’s will, hence they are also called involuntary muscles. These muscle cells are long with pointed ends (spindle shaped) and arranged in bundles. Each cell is uninucleated (having a single nucleus).

Smooth muscles are found in alimentary canal and blood vessels. The movement of food in the alimentary canal or the contraction and relaxation of blood vessels are involuntary movement. These are also found in the iris of the eye, in uterus and in the bronchi of the lungs.

(c) Cardiac muscles: These muscles are exclusively present in the heart. These muscles of the heart show rhythmic contraction and relaxation throughout life. They are striated but involuntary muscles. Heart muscle are cylindrical and uninucleated. They are branched and form a network in the walls of the heart.

The cells of the nervous tissue are called nerve cells or neurons. A neuron or nerve cell is structural and functional unit of the nervous tissue. It consists of:

● Cell body or cyton

● Axon

● Dendrons or dentrites

Cell body or cyton has a prominent nucleus and cytoplasm. Cell organelles like golgi bodies, mitochondria, etc are also present in the cytoplasm. From the cell body extend out two kinds of cytoplasmic extensions called dentrites and axons. The axon is covered by a fatty myelin sheath. Myelin sheath is discontinuous and broken at intervals by nodes of Ranvier. Axons

Axons usually a long, unbranched, cylindrical process that ends in many terminal end fibres. The axon ending of one nerve cell is lossely placed on the cell body of another nerve cell. Synapse is the junction between the terminal part of one axon and the dendrite of the adjacent neuron. Synapses helps in the transmission of impulses from one neuron to another.The other small branch given out by the cyton are called dendrons which branch further into numerous thin hair-like dentrites.

Amoeba is a single cell unicellular organism. It performs all vital life activities like respiration, intake of food, exchange of respiratory gases, excretion, reproduction.

In multicellur organisms, each kind of cell is structured to perform all vital life activities and one specific function as a component of tissues.

A tissue is a group of cells of the same type or mixed type having a common origin and performing a common function.

There are two types of plant tissues -Meristematic and permanent.

Meristematic tissue is present in plants but absent in animals.

Division of labour is adaptation of different parts of an organism to carry out different functions.

Tissues with dead cells are more common in plants.

Animals consume more energy as compared to plants as they move around in search of food, mates and shelter.

Active movement of animals and sedentary habit of plants contribute more to difference in organ system of plants and animals.

(i) Apical meristem- Shoot apes;

(ii) Lateral meristem- Cambium.

Meristematic tissues are found in apical, intercalary and lateral positions in plants.

A permanent tissue is a group of cells which temporarily or permanently cease to divide have assumed a definite form and size.

Simple tissue is made up of only one type of cells that carry out the same function.

Three types of simple tissues of plants are: Parenchyma, collenchymas and selerenchyma.

The main function of parenchyma is to provide support to the plant and also store food.

Collenchyma tissue is irregularly thickened at the corners due to the depositon of pectin and cellulose.

Lignin is deposited in the cell wall of sclerenchyma.

Collenchyma is a simple permanent tissue which provides mechanical strength as well as flexibility to the plant organs.

Tissue which is composed of two or more types of cells but contribute to a common function is called complex tissue.

(a) Xylem helps in conduction of water and minerals.

(b) Phloem helps in conduction of food.

(a) The common name of xylem is wood.

(b) The common name of phloem is bast.

Companion cell is living cell which is attached to the lateral side of sieve tube.

Sclerenchyma is a type of simple permanent tissue which is used for making ropes.

Cork is the example of protective tissue in the plants.

Stomata are tiny pores present on the leave’s surface which help in the exchange of gases and in transpiration.

Lateral meristem is responsible for growth in grith of stem and root.

Four main types of animal tissues are:

(i) Epithelial tissues. (ii) Muscular tissues, (iii) Connective tissues, (iv) nervous tissue.

Squamous epithelium protects the underlying parts from germs, harmful chemicals and injury.

It is found in the alveoli of lungs and blood vessels.

Goblet cell is a simple columnar epithelial cell which is modified to secrete mucus. It is seen in the intestine and other parts of the alimentary canal.

It has finger-like projections called cilia on the outer suface of columnar epithelial. These cilia can move, and their movement pushes the mucus forward to clear it.

Connective tissues are most abundant and widely distributed in the body of complex animals. The cells of connective tissue are loosely spaced and embedded in an inercellular matrix. The matrix may be jelly like, fluid, dense or rigid.

The protein fibres of connective tissue are white fibres of collagen, yellow fibres of elastin and reticular fibres of reticulin.

The various cells of connective tissue are fibroblasts, adipose cells, macrophages, mast cells and lymphocytes.

(i) Tendons is a dense connective tissue which connects a bone with a muscle.

(ii) Ligaments are elastic structures which connect bones to bones.

(iii) Cartilage is tough, flexible connective tissue found in all vertebrates. Its solid matrix is composed of proteins and sugars. The cells of cartilage are called chondrocytes. They don’t have blood vessels.

Cartilage is present in the tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in adults.

The cells of bones are called osteocytes. Bone cells are embedded in a hard matrix that is composed of calcium and phosphorus compounds.

Types of white blood cells (WBCs) are:

(i) Eosinophils; (ii) Basophils; (iii) Neutrophils; (iv) Monocytes; (v) Lymphocytes

Blood platelets occur in human blood. They are minute, colourless, biconvex and non-nucleated blood corpuscles. They help in clotting of blood at the site of injury.

Three types of muscles occur in animals namely striated muscles, smooth muscles and cardiac muscles.

A neuron or nerve cell is the structural and functional unit of nervous system. A typical neuron consists of cell body or soma, dendrites and axon.

Epithelial tissue is the simplest animal tissue which composed of one or more layer of cells. This tissue protects the entire animal body.

On the basis of arrangement of layers, epithelial tissue is classified into two types: simple epithelium and stratified epithelium.

(a) Blood vessels; (b) intestine.

(a) Glandular epithelium is present in sweat gland.

(b) Germinal epithelium is present in testis.

Simple squamous epithelial cells are extremely thin and flat which allows diffusion of substances through it.

Connective tissues are most abundant and widely distributed in the body of complex animals

Bone is a dense connective tissue in which matrix is solid.

Adipose tissue is also known as fat storing tissue. It is present in hump of camel and blubber of ehale.

Areolar tissue is commonly known as packaging tissue. It is basic type of connective tissue present all over in the body.

Ligament connects two bones together at joints.

Cartilage is present at the tip of nose and in the external ear.

Cartilage contains chondrin and bone contains ossein respectively.

Blood is fluid connective tissue which has fibreless matrix.

Serum is blood plasma of blood from which fibrinogen is removed.

WBC protects our body against infections.

RBC acts as a transportor of oxygen and carbon dioxide as it contains respiratory pigment called haemoglobin.

Blood platelets help in clooting of blood at the site of injury.

Differences between blood and lymph:

Lymphocytes are WBCs which are most abundant in lymph.

Ciliated epithelium is found in respiratory tract.

(a) Skeletal or striated muscle fibre is multinucleated.

(b) smooth or unstriated muscle fibre is long and spindle shape.

Skeletal or striated muscle gets fatigued very soon. These are voluntary muscels.

The muscle of heart is known as cardiac muscle.

Skeletal and cardiac muscles are two types of striated muscle fibres.

Smooth muscle or unstriated muscle is commonly found in visceral organs.

Cardiac muscle fibre contains intercalated discs.

(a) Sensory neurons carry impulses towards brain.

(b) Axon is long, branch process of neuron which carries impulses away from cyton.

In unicellular organisms, a single cell performs all basic functions. For example, in Amoeba. But in multicellular organisms (e.g., human), there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialised function is taken by a different group of cells or tissue. Thus, multicellular organisms show division of labour.

A group of cells that are similar in structure and/or work together to achieve a

particular function forms a tissue.

Meristematic tissue consists of cells which are not differentiated and which are cabable of cell division. It is found on those regions of the plant which grows.

The meristematic cells are full of cytoplasm and have a big nucleus.

The cell wall of meristematic cell is thin and made up of cellulose.

Parenchyma which contains chlorophyll and takes part in photosynthesis, is called chlorenchyma.

Parenchyma is a type of simple permanent tissue. It is present in soft parts of the plant like cortex, pith, palisade and some parts of the flower.

Parenchyma is a type of simple permanent tissue. It is present in soft parts of the plant like cortex, pith, palisade and some parts of the flower.

Pholem is mainly responsible for the conduction or transport of organic food prepared by the plant.

Collenchyma tissue are found below epidermis in leaves and stem.

The tissues formed by meristematic tissues take up a specific role and lose the ability to divide further. As a result, they form a permanent tissue. This process of taking up a permanent shape, size, and a function is called differentiation. Cells of meristematic tissue differentiate to form

different types of permanent tissue.

Collenchyma is generally absent in monocot stems and leaves.

The grit of pear is formed of stone cells also known as sclereids.

Sclerenchyma is a type of simple permanent tissue. The cells of this tissue are dead. Tracheids and vessel are elongated, tubular cells of xylem (complex permanent tissue). These are non-living cells.

Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma.

Parenchyma, collenchyma and sclerenchyma are types of simple tissue whereas xylem is a type of complex tissue.

Xylum parenchyma cells are living. The parenchyma stores food and helps in the sideway conduction of water.

The phloem parenchyma stores food material and other substances like resins, latex and mucilage. It is absent in monocot stem.

Phleom is composed of four types of elements i.e., sieve tubes, campanion cells, phloem parenchyma and phloem fibers or bast fibers. All type of cells are living except bast fibers.

Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres. The cells have thick walls, and many of them are dead cells.

Bichat is also known as “Father of histology”.

The term tissue was given by Bichat.

Epithelial tissue always has an exposed outer surface and an inner surface anchored to connective tissue by a thin, non-cellular structure called the basement membrane.

Simple squamous epithelial cells are extremely thin and flat and form a delicate lining. Squamous epithelial tissue forms the inner lining of a blood vessel.

Glands develop from epithelial tissue. They may be unicellular or multicellular.

An epithelium is a tissue composed of one or more layer of cells covering the external surface and internal body organs.

In the respiratory tract, the columnar epithelial tissue also has cilia, which are hair-like

projections on the outer surfaces of epithelial cells. These cilia can move, and their movement pushes the mucus forward to clear it. This type of epithelium is thus ciliated columnar epithelium.

Nasal and genital tracts are lined by pseudostratified epithelium.

Skin epithelial cells are arranged in many layers to prevent wear and tear. Since they are arranged in a pattern of layers, the epithelium is called stratified squamous epithelium.

Cardiac muscle fibres are branched, striated and involuntary. These muscles are exclusively present in the heart.

Under the microscope, striated muscles show alternate light and dark bands or striations when stained appropriately. As a result, they are also called striated muscles.

Connective tissues are most abundant and widely distributed in the body of complex animals.

The cells of connective tissue are embedded in a matrix. The matrix may be jelly like, fluid, dense or rigid. It is produced by fibroblasts.

Tendons and ligaments are dense connective tissue.

Ligament is a dense connective tissue which connects a bone with bone.

Matrix of cartilage is made up of chondrin.

Blood consists of plasma (55%) and blood corpuscles (45%).

Monocytes are largest blood cells. These are white blood cells.

Each neuron has a single long part, called th axon and many short, branched parts called dendrites.

Blood consists of plasma and blood corpuscles. Plasma is a liquid part of blood which contains 85-90% water.

Tendon is a fibrous (dense) connective tissue which connects a muscle with a bone.

Parenchyma tissues are the most abundant tissues found in plants.

The meristem which occurs at the growing tips of roots and shoots and increases the length of the stem and root is called apical meristem.

It is responsible for growth in grith of stem or root.

The prcess of taking up a permanent shape, size and a function is called differentiation.

Parenchyma, collenchyma sclerenchyma, Tracheids, vessels, companion cells, sieve tubes

In aquatic plants, large air cavities are present in parenchyma to give buoyancy to the plants to help them float. Such a parenchyma type is called aerenchyma.

The cell wall is generally unevenly thickened in collenchymas. The walls are rich in hemicellulose.

Sclerenchyma is the main mechanical tissue of the plants. It provides strength to the plants and enables them to withstand various strains.

Epiblema is the outermost covering of the root forming by single layer of compactly arranged parenchyma cells.

Commercial cork is obtained from the cork oak tree.

Xylem vessels and tracheids are two elements of xylem tissue which help in the transportation of water.

The cells of phloem are called sieve tubes. Sieve tubes are conducting element of phloem which is responsible for transportation of food.

Companion cells are found associated with sieve tubes and helps in conduction of food.

Root hair is formed by the extension of epidermal cell in roots of a plant.

Squamous epithelium is also called pavement epithelium as it is made up of single thin layer of flattened cells.

Bone cells are embedded in a hard matrix that is composed of calcium and phosphorus compounds.

Tendon is a fibrous (dense) connective tissue which connects a muscle with a bone.

Smooth muscles are found in alimentary canal and accomplish peristalsis movement.

Muscular tissue is responsible for movement in our body. The cells of this tissue contain special proteins called contractile proteins, which contract and relax to cause movement.

The normal RBC range for men is 4.7 to 6.1 million cells per microliter. The normal RBC range for women is 4.2 to 5.4 million cells per microliter.

In human, it ranges from 5000 to 11000 leucocytes/mm³ blood.

The number of blood platelets is 2,50,000-300,000 per cubic mm.

A neuron consists of a cell body or cyton with a nucleus and cytoplasm, from which long thin

hair-like parts arise.

Myelin (medullary) sheath is a fatty covering that surrounds axon of nerve fibres. It insulates the nerve fibre (axon) and prevents leakage of ions.

The nerve fiber which is surrounded by a myelin sheath is called medullated nerve fiber. In this nerve fiber, conduction of nerve impulse is faster.

Division of labour is adaptation of different parts of an organism to carry out different functions. Hence, there are several kinds of tissues, each with specific properties to carry out specific function in the body.

Lodged shoots become upright due to activity of intercalary meristem.

cork cambium and vascular cambium help in secondary growth of stem and root.

The tissue of a leaf that is found in between upper and lower epidermis is the mesophyll.

Stomata are tiny pores present on the leave’s surface which help in the exchange of gases and in transpiration.

Collenchyma is the simple tissue that provides flexibility to soft aerial plant parts to withstand against winds.

The other name of cork cambium is phellogen.

The another name of cork is phellem.

The cell wall of cork is coated with suberin, a waxy substance which which makes these impermeable to water and gases.

Two types of conducting tissues are found in plants- Xylem and Phloem.

Sieve tube is multicellular.

The sclerenchyma fibers are of great economical importance since they constitute the source material for many fabrics, hemp, flex, jute.

Tracheid is a conducting element of xylem.

Each stomata is surrounded by a pair of guard cells. Guard cells regulate the opening and closing of stomata.

White blood cells are protect our body from various germs that infact our body, hence they are known as soldiers of the body.

Eosinophils increases during worm infection.

Bone and cartilage cells reside in small spaces within the matrix that are called lacunae.

Adipose tissue forms blubber of whale and hump of camel.

Tendon is a form of connective tissue.

Columnar epilthelium has pillar-like cells.

Nodes of ranvier occur in nerve cells.

Boutons are the swollen endings of the axon where synapsis with other neurons occur.

Connective tissue cells neurolemma are called epineurium.

Cardiac muscles seldom get fatigues because of extreme endurance exercises.

Group of cells that are similar in structure and perform same function is called a tissue.

Tissue provide structural strength, mechanical strength and show division of labour.

(i) Plants are stationary or fixed as they don’t move while animlas move around in search of food, mates and shelter.

(ii) The growth in plants is limited to certain regions, while this is not so in animals.

Meristematic tissue: It is a group of cells which constantly divide and produce cells indefinitely throughout the life of a plant. Meristematic tissue is found in all the growing parts of a plant such as root tip, shoot tip, etc.

Characteristics of meristematic cells:

(i) The cells of this tissue are very active. They have dense cytoplasm.

(ii) The cell wall is thin and made up of cellulose.

(iii) They lack vacuoles.

(iv) They have big nucleus.

A permanent tissue is a group of cells which temporarily or permanently cease to divide.

The cells of this tissue have smaller nuclei and well developed vacuoles. They may be dead or alive, thin walled or thick walled.

Structure: Parenchyma is a simple, permanent living tissue which is made up of thin-walled cells. The cells of this tissue are oval, elongated, and loosely packed with large intracellular space. Their cell wall is made up of cellulose. Each cell encloses a large central vacuole, cytoplasm and a prominent nucleus.

Location: The parenchyma tissue is present in soft parts of the plant such as cortex, pith, palisade and some parts of the flower.

Functions: Parenchyma tissue provides support to plants and also stores food. In some situations, it contains chlorophyll and performs photosynthesis.

Collenchymas is a type of permanent tissue which is found few layer below the epidermis of leaves and stem. The cells of this tissue are living, elongated and tightly packed with no inter-cellular space. The cells have small nucleus, large vacuoles and thin cell wall but irregularly thickened at the corners.

Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

Sclerenchyma is a supporting tissue. It is the tissue which make plant hard and stiff.

Location: This tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts.

Structure: The cells of this tissue are dead. They are long, elongated, narrow, thick walled and lignified. These consists of fibres and sclereids.

Xylem is a complex vescular tissue which is composed of several types of cells. Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.

The cells of this tissue have thick walls and many of them are non-living.

(i) Tracheids: These are long elongated tubular cells. Tracheids cells are dead. Its main function is conduction of water and minerals from root to stem.

(ii) Vessels: These are pipe-like structure. Vessels are dead and have lignified cell wall. They also participate conduction of water and minerals.

(iii) Xylem parenchyma: These are living cells which store food material.

(iv) Xylem fibres: These are dead cells provide mechanical support to the plant.

Phloem is made up of four types of elements: Sieve tubes, companion cells, phloem fibres and the phloem parenchyma.

(i) Sieve tubes: These are tubular cells with perforated walls. These cells are responsible for transportation of food and nutrients.

(ii) Companion cells: These cells are found associated with sieve tubes and connected with it by simple pits. These cells are long, narrow and thin walled. These cells are living.

(iii) Phloem fibres: They have thick cell wall and they provide mechanical support to plant.

(iv) Pholem parenchyma: These cells are living and often cylindrical in shape.

The transport of food from leaves to other parts of the plant is called translocation

Epithelial tissue is the simplest animal tissue which composed of one or more layer of cells covering external and internal body organs.

Characteristics of epithelial tissue:

(i) The cells of epithelial tissue are tightly packed and form continuous sheets.

(ii) Epithelial cells have small amount of cementing material between them and almost no intercellular space.

(iii) The surface of cells may be smooth, columnar or cuboidal.

(iv) The cells of the lowermost layer rest on non-cellular basement membrane which separates it from the underlying connective tissue.

Functions: Epithelial tissue performs following functions:

(i) It protects the organs which it covers.

(ii) It absorbs water and other nutrients inside the body.

(iii) Some epithelial cells secrete ear wax, mucus and digestive juices.

(iv) It keeps different organs separate.

The cells of squamous epithelium tissue are extremely thin and flat and form a delicate lining. It is found in the alveoli of lungs and blood vessels and protects the underlying parts from germs, harmful chemicals and injury.

It is composed of a single layer of cube-like cells. It is found in kidney tubules and salivary glands. It provides mechanical support to organs and helps in absorption and excretion.

It is composed of a single layer of tall and slender cells. Their nuclei are located at the base. Free surface may have microvilli. It is generaly found in the lining of stomach and intestine and help in secretion and absorption.

Muscular tissue is a contractile tissue made up of muscles. Muscles consists highly specialised cells called muscle fibres. This tissue is responsible for movement in our body.

Striated muscles are also called voluntary muscles as their movement is under our will. The cells of striated muscles are long, narrow, cylindrical, unbranched with blunt ends. They have multi nucleus.

These muscles are also called skeletal muscles because they are mostly attached to bone and help in body movement. These muscles show alternate light and dark band or striations when stained appropriately. As a result, they are also called striated muscles.

Smooth muscles also called as unstriated muscles as they lack transverse striations. They are not under the control of one’s will, hence they are also called involuntary muscles. These muscle cells are long with pointed ends (spindle shaped) and arranged in bundles. Each cell is uninucleated (having a single nucleus).

Smooth muscles are found in alimentary canal and blood vessels. The movement of food in the alimentary canal or the contraction and relaxation of blood vessels are involuntary movement. These are also found in the iris of the eye, in uterus and in the bronchi of the lungs.

These muscles are exclusively present in the heart. These muscles of the heart show rhythmic contraction and relaxation throughout life. They are striated but involuntary muscles. Heart muscle are cylindrical and uninucleated. They are branched and form a network in the walls of the heart.

Connective tissues are most abundant and widely distributed in the body of complex animals. The cells of connective tissue are loosely spaced and embedded in an inercellular matrix. The matrix may be jelly like, fluid, dense or rigid.

Functions of connective tissue:

(i) It binds different structure with another like skin with muscles and muscles with bones, etc.

(ii) It forms a supporting framework of cartilage and bones in the body.

(iii) Blood flows and transports gases, digested food, hormones and waste materials to different parts of the body.

(iv) Adipose tissue helps in the storage of fats.

It is the most fundamental type of connective tissue which is found all over the body. This tissue is present in spaces in between the skin and muscles, around blood vessels and nerves and in the bone marrow.

Areolar connective tissue has homogenous, semi-solid gel like ground substance called matrix in which various types of cells and collagen fibres and elastic fibres are embedded. It contains fibroblast cells, mast cells and macrophages. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

It is fat storing connective tissue which is found mainly beneath the skin. The adipose tissue consists of several spherical or oval adipose cells (adipocytes or fat cells). Each adipose cell contains fat globules. It is found below the skin, around the internal organs like heart, kidneys and eyeballs.

Functions: (i) It acts as an insulator.

(ii) Provides support and protection to the vital organs.

(iii) It acts as a storage of fat.

Dense connective tissue is of two types- tenonds and ligaments.

Cartilage is compact with widely spaced cells. Its solid matrix is composed of proteins and sugars. The cells of cartilage are called chondrocytes. They don’t have blood vessels.

Cartilage is present in the tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in adults. Cartilage smoothens bone surfaces at joints. It provides support and flexibility to the body parts.

Bone is a strong and non-flexible tissue. The cells of bones are called osteocytes. Bone cells are embedded in a hard matrix that is composed of calcium and phosphorus compounds. Each cell is enclosed in a small cavity called the lacuna.

Functions:

(i) It provides shape to the body.

(ii) It forms the framework that supports the body.

(iii) It anchors the muscles.

(iv) It protects the vital body organs like brain, lungs, etc.

Blood is a fluid connective tissue which circulates in our body. The main components of blood are plasma (55%) and blood corpuscles (45%).

Plasma is straw-coloured fluid which contains 85-90% water and 5-10% other substances like proteins, salts and hormones. There are three types of blood corpuscles:

● RBC (Red blood cells)

● WBC (White blood cells), and

● Platelets

The functions of blood:

(i) Transport oxygen from the lungs to different parts of the body.

(ii) Transport CO₂ from the body tissues to the lungs.

(iii) Transport digested food i.e., glucose, amino acids, etc. from alimentary canal to various parts of the body for energy, growth and repair.

(iv) Transport excretory waste product called urea from the liver to the kidneys for removal as urine.

(v) Plasma regulates water balance in the body.

(vi) Regulates the body temperature.

Lymph is a colorless or slightly yellowish fluid. It is a medium of circulation in human body which flows only in one direction - from body tissues to the heart.

The functions of lymph are:

(i) Lymph helps in removing the waste products.

(ii) Lymph carries digested fat from the small intestine to the entire body.

(iii) Lymph nodes contain lymphocytes which kill the germs or foreign bodies.

The cells of the nervous tissue are called nerve cells or neurons. A neuron or nerve cell is structural and functional unit of the nervous tissue. It consists of:

● Cell body or cyton

● Axon

● Dendrons or dentrites

Cell body or cyton has a prominent nucleus and cytoplasm. Cell organelles like golgi bodies, mitochondria, etc are also present in the cytoplasm. From the cell body extend out two kinds of cytoplasmic extensions called dentrites and axons. The axon is covered by a fatty myelin sheath. Myelin sheath is discontinuous and broken at intervals by nodes of Ranvier.

Axons usually a long, unbranched, cylindrical process that ends in many terminal end fibres. The axon ending of one nerve cell is lossely placed on the cell body of another nerve cell. The other small branch given out by the cyton are called dendrons which branch further into numerous thin hair-like dentrites.

Collenchyma tissue provides flexibility to plants so that they can easily bend without breaking. It also provides mechanical support to plants.

Lignin, a chemical substance is deposited in the secondary wall of sclerenchyma.

(a) Collenchyma

(b) Sclerenchyma

(c) Parenchyma.

Skeletal connective tissue forms the endoskeleton of the body. It includes bones and cartilage.

Functions of skeletal connective tissue:

(i) It provides support to the body.

(ii) Protects the vital organs of the body like brain, ear, heart, lungs etc.

(iii) It anchors the muscles and provide movement to animal body.

Synapse is the junction between the terminal part of one axon and the dendrite of the adjacent neuron. Synapses helps in the transmission of impulses from one neuron to another.

White fibre - collagen protein

Yellow fibre - elastin protein

Functions of microvilli:

(a) They increase the absorptive surface of the intestinal cell (enterocyte) and

(b) They increase the surface area available for reactions.

Myelin (medullary) sheath is a fatty covering that surrounds axon of nerve fibres. It insulates the nerve fibre (axon) and prevents leakage of ions.

Lymph is a colorless or slightly yellowish fluid which is called the middleman between tissues cells and blood.

(a) Squamous epithelium

(b) 1. Cytoplasm,

2. Nucleus,

3. Cement substance,

4. Basement membrane.

(c) Squamous epithelium protects the underlying body parts such as skin, nose, etc. from germs, harmful chemicals and injury.

(a) 1. Tendon, 2. Muscle, 3. Ligament, 4. Bone.

(b)

(a) It is neuron, structural and functional unit of nervous system.

(b) 1. Dendrite,

2. Cyton or cell body,

3. Axon.

(c) It is located in brain and spinal cord.

(a) Muscular tissue

(b) 1. Sarcoplasm,

2. Intercalated disc,

3. Nucleus.

(c) It is cardiac muscles which are exclusively present in the wall of heart.

(a) The figure represents the location of meristematic tissue in plant body.

(b) 1. Apical meristem,

2. Intercalary meristem;

3. Lateral meristem.

(c) Apical meristem increases the length of the stem and root.

Lateral meristem is responsible for growth in grith of stem and root.

(a) It is simple and living parenchyma tissue.

(b) 1. Cytoplasm;

2. Nucleus,

3. Vacuole,

4. Intercellular space,

5. Cell wall.

(c) The main function of parenchyma is the storage of food.

When blood circulates in the body, it passes through all the organs and thus connects

different tissues and organs of the body. Hence it is considered to be a connective tissue.

Apical meristems are the growing parts of the roots and stems and are present at the tips of roots, branches, leaves and shoots. If the apical meristems are damanged or cut, the growth of that part of the plant will stop.

Bone marrow is responsible for the production of blood cells in the body. If bone marrow is destroyed, the formation of white blood cells, red blood corpuscles and platelets will stop.

Blood platelets are responsible for clotting of blood. If blood platelets are removed from the blood, clotting will not happen after injury and bleeding will continue. This might lead to the death of the injured person.