BIOLOGY PROJECT WORK

Kendriya Vidyalaya No.2

BikanerHoliday’s HomeworkSubject-Biology

Submitted to,Mr.Virendra KumarP.G.T. Biology

Submitted by,Aryalakshmi.CXI th Science ’A’

CHAPTER - 7STRUCTURAL ORGANISATION

IN ANIMALS

Contents…1. Animal Tissues 2. Cockroach

Introduction…In preceding chapters, we came across a large variety of organisms, both unicellular and multicellular, of the animal kingdom. In unicellular organisms, all the functions like digestion, respiration & reproduction are performed by a single cell.

In the complex body of multicellular organisms, the same basic functions are carried out by different group of cells in a well organised manner.In this chapter, we are going to study that how do these cells in the body of a multicellular organism work together, taking the example of morphology & anatomy of a covkroach.

Various tissues in a bird’s body

Various tissues in a mouse’s body

Various tissues in a human being’s body

Tissue  is a group of similar cells along with intercellular substances which perform a specific function.

Tissue

Cell• Fund

amental unit of life

Group of cells performing similar functions Tissue

Organ• Group of

tissues join together to form organs

Organ system• Group of

organs forms organ system

Individual • Group of

organ systems forms an individual

In Multicellular Organisms…

ANIMAL TISSUES

Animal tissues are classified into four types:

Animal tissues

Epithelial tissues

Connective tissues

Muscular tissues

Neural tissues

Epithelial tissues These tissues commonly called epithelium.Has free surface, which faces either a body fluid or the outside environment.Cells are compactly packed with little intercellular matrix.There are two types of epithelial tissues on the basis of composition:

Simple epithelium.Compound epithelium.

Epithelial tissues

Simple epithelium Compound epithelium

Simple epithelium is composed of a single layer of cells and functions as a lining for body cavities, ducts and tubes.The Compound epithelium consists of two or more cell layers and has protective function as it does in our skin.

Definitions

Simple epithelium

Compound epithelium

It is composed of only one layer of cells. It is mainly involved in the function of absorption and secretion. It is present in the lining of the stomach, intestine.

It is composed of many layers of cells. It is mainly involved in the function of protection and has a limited role in absorption and secretion. It is present in the lining of the pharynx and buccal cavity.

On the basis of modification,

Simple epithelium

Squamous epithelium

Cuboidal epithelim

Columnar epithelium

Squamous epitheliumComposition: made of single thin layer of flattened cells with irregular boundaries.Location: found in the wall of blood vessels and air sacs of lungs.Function: as diffusion boundary.

Cuboidal epithelium Composition: made of a single layer cube – like cells.Location: found in ducts of glands and tubular part of nephrons in kidneys.Function: main function is secretion and absorption.

Columnar epitheliumComposition: made of a single layer of tall and slender cells.Their nuclei located at the base.Free surface may have microvilli.Location: found in the lining of stomach and intestineFunction: helps in absorption and secretion.

Ciliated epithelium It is a modified Cuboidal or columnar epithelium.Cell bears cilia on their free surfaces.Location: found in the inner surface of hollow organs like bronchioles and fallopian tubes.Function: to move particles or mucus in a specific direction over the epithelium.

Glandular epitheliumIt is a modified Cuboidal or Columnar Epithelium.Function: get specialized for secretion.Location:

1. Simple glands having unicellular and isolated cells of alimentary canal.

2. Multicellular glands: consisting of cluster of cells, as in salivary gland.

4. Exocrine gland: the secretory product transported to a point by means of a duct. These glands secrete mucus, saliva, ear wax, milk, digestive enzymes etc

5. Endocrine gland: commonly called as ductless gland, because the secretory products directly poured into blood. The glands secretes hormone.

Compound epithelium

Composition: made of more than one layer of cells.Functions:limited role in absorption and secretion.

main function is to provide protection against chemical and mechanical stresses.

Location: they cover the dry surface of skin, moist surface of buccal cavity, pharynx, inner lining of duct of salivary gland and pancreatic duct.

Cell junctionCells of the epithelium are held together with little intercellular matrix.Cell junction provide structural and functional link between the cells

Cell junction

Tight junction Adhering junction Gap junctions

1.Tight junction: help to stop substances from leaking across a tissue.

2.Adhering junctions: perform cementing to keep neighboring cells together.

3.Gap junctions: facilitate the cells to communicating the cytoplasm of adjoining cells, for rapid transfer of ions, small molecules.

Adhering junction

Connective tissuesMost abundant and widely distributed tissues.Special function of linking and supporting other tissues/organs of the body.Connective tissues include areolar, adipose, cartilage, bone, and blood.

In all connective tissue except blood, the cells secrete fibres of proteins called collagen and elastin.The fibre provides strength, elasticity and flexibility to the tissue.Presence of ground substance  or matrix in between the cells, modified polysaccharides.

Specialized Connective Tissues

Loose connective tissue

Has cells and fibres loosely arranged in a semisolid ground substance.Loose connective tissues

Areolar tissue Adipose tissue

Areolar TissueAreolar tissue is one example of loose connective tissue.Composition: it contains cell like fibroblasts (secretes fibres), macrophages and mast cells.Location: present beneath the skin.Function: it supports the framework for epithelium.

Adipose tissueAnother type of loose connective tissues.Location: mostly beneath the skin.Function: Cells of this tissue specialized to store fats called adipocytes.

Dense connective tissue

Fibres and fibroblasts are compactly packed.

Dense connective tissue

Dense regular tissue Dense irregular tissue

Dense regular connective tissues

Dense irregular connective tissues

In dense regular connective tissues, collagen fibres are present in rows between parallel boundless fibres. They are present in tendons and ligaments.

In dense irregular connective tissues, fibres are arranged irregularly.

They are present in the skin.

Dense regular tissues

Orientation of fibres shows a regular pattern.The collagen fibres are present in rows between many parallel bundles of fibres.It consists of tendons & ligaments.

Dense regular tissues

Tendons Ligaments

Tendons attach bones to muscles may also attach muscles to structures such as the eyeball. A tendon serves to move the bone or structure.A ligament is a fibrous connective tissue which attaches bone to bone, and usually serves to hold structures together and keep them stable.

Dense irregular tissues

•Fibroblasts and many fibres are oriented differently.•Location: this tissue present in skin.

Specialized Connective

Tissues Specialized connective tissue

Cartilage Bone Blood

CartilageIntercellular material of cartilage is solid.Chondrocytes are the cells of cartilage.Pliable and resists compression.Cells are enclosed in small cavities within the matrix.Most of the cartilage of the embryo replaced by bones in adult.Location: present in nose tips, ear pinna, between adjacent vertebrae.

BonesHave hard and non pliable matrix or ground substance.The matrix is rich in calcium salts and collagen fibers which give the bone its strength.Provides the structural frame of human body.Support and protect the soft tissues and organs.The bone cells called Osteocytes are present in fluid filled cavity called lacunae.Sustain body weight.Attached with skeletal muscles meant for locomotion.Bone marrow is the site of production of Red blood cells.

Structure of a bone

Blood Blood is a fluid connective tissue.It is the main circulating fluid that helps in the transport of various substances.It consists of:

Blood

Plasma Red blood cells (RBC)

White blood cells (WBC)

Muscular tissuesEach muscle is made of many long, cylindrical fibres arranged in parallel arrays.Each fibre composed of numerous fine fibrils, called myofibrils.Muscle fibres contracts in response to stimulus.Muscle plays a great role in movement and locomotion.

Muscular tissues

Skeletal (striated) muscular tissue

Smooth (non-striated) muscular tissue Cardiac muscular tissue

Skeletal muscle(Striated)

Closed attached to the skeleton or bone and cartilage.Muscle cells are unbranched and multinucleated.A number of muscle fibres are bundled together in parallel fashion.A sheath of tough connective tissues encloses several bundles of muscle fibres

Smooth muscle(Non-Striated)

The smooth muscle fibres tapers or pointed at both endsDo not show cross striation.Cell junctions hold them together.They are bundled together in a connective tissue sheath.Present in wall of blood vessels, stomach and intestine.They are involuntary in nature.

Cardiac musclesContractile muscular tissue present in heart.Cell junctions fuse the plasma membranes of cardiac muscles cells and make them stick together.Communication junction or intercalated discs at some fusion points allow the cells to contract as a unit.Muscle cells are branched and uninucleated.

Neural tissuesNeural tissues exert greatest control over body’s response to changing condition.Neurons are the units of nervous tissues.Neuroglial cells non-conducting and protects and support neurons.Neuroglia makes up more than one-half the volume of neural tissue.Electrical impulse is conducted through the plasma membrane of neuron.

Diagram of neural tissue

Chapter: 5

Cockroach

Morphology of cockroach

The common species of cockroach periplaneta americana .

The body of the cockroach is segmented and divisible into three distinct region.

(i).Head(ii)Thorax(iii)AbdomenBody covered by a hard chitinous exoskeleton

brown in colour .

• Segment , exoskeleton has hardened plates called sclerites that are joined to each other by a thin and flexible articular membrane

.

Parts of head region

• Head is triangular in shape and lies anteriorly at right angle to the longitudinal body axis .

• It is formed by the fusion of six segments and show great mobility in all direction due to flexible neck.

• The head capsule bears a pair of compound eyes.• Antennae have sensory receptors that help in

monitoring the environment. • Anterior end of the head bears appendages

forming biting and chewing type of mouth parts.

• The mouthparts consisting of a labrum;• A pair of mandibles• A pair of maxillae and a labium• A median flexible lobe , acting as tongue , lies

within the cavity enclosed by the mouthparts.

Thorax

• Thorax consist of three parts; • Prothorax• Mesothorax • Metathorax• The head is connected with thorax by a short

extension of the prothorax known as neck.• Each thoracic segments bears a pair of walking

lags.

The first pair of wings arises from mesaothoraxThe second pair from metathorax.Forewings (mesothoracic) called tegmina are

opaque dark and leathery and cover the hind wings when at rest .

The hind wings are transparent , membranous and are used in flight .

Abdomen• The abdomen in both males and females

consist of 10 segments .• In females , the 7th sternum is boat shaped and

together with the 8th and 9th sterna forms a brood or genital pouch whose anterior contains female gonopore ,spermathecal pore and collateral gland.

• In males genital pouch or chamber lies at the hind end of abdomen bounded dorsally by 9th and 10th terga and ventrally by the 9th

sternum .

It contains dorsal anus, ventral male genital pore and gonapophysis .

Males bear a pair of short , thread like anal style which are absent in females cockroach.

In both sexes ,the 10th segments bears a pair of jointed filamentous structures called anal cerci .

Anatomy of cockroach.

•Alimentary canal system• The alimentary canal present in the body cavity is divided

into three parts ;• Foregut • Midgut• Hindgut • The mouth opens into a short tubular pharynx leading to a

narrow tubular passage called oesophagus .

.

•This opens into a sac like structure called crop used for storing food •The crop is followed by gizzard or proventriculus . •It has an outer layer of thick circular muscles and thick inner cuticle forming six highly chitinous plate called teeth . •Gizzard helps in grinding the food particles . •A ring of 6-8 blind tubules called hepatic or gastric caecae is present at the junction of foregut & midgut which secrete digestive juice .

• At the junction of midgut and hindgut is present another ring of 100-150 yellow coloured thin filamentous tubules .

• They help in removal of excretory products from haemolymph .

• The hindgut is broader than midgut and is differentiated into ileum , colon and rectum the rectum opens out through anus .

Blood circulatory system

• Blood vascular system of cockroach is an open type.

• Blood vessels are poorly developed and open into space

• Visceral organs located in the are bathed in blood .

• The haemolymph is composed of colourless plasma and

• Heart of cockroach consist of elongated muscular tube lying along mid dorsal line of thorax and abdomen .

• It is differentiated into funnel shaped chamber with ostia on either side .

• blood from sinuses enter heart through ostia and is pumped anteriorly to sinuses again .

Respiratory system of cockroach

• the respiratory system consist of a network of trachea , that open through 10 pair of small holes called spiracles present on the lateral side of the body .• Thin branching tubes carry oxygen

from the air to all part .• The opening of the spiracles is

regulated by the sphincters . Exchange of gases take place at the tracheoles by diffusion .

Excretory system of cockroach

• Excretion is performed by malpighian tubules.• Each tubules is lined by glandular and ciliated

cells .• They absorb nitrogenous waste product and

convert them in to uric acid which is excreted out through the hindgut the hindgut .

• This insect is called uricotelic . • The fat body nephrocytes and urecose glands also

help in excretion .

Nervous system of cockroach

• The nervous system of cockroach consist of a series of fused segmentally Arranged ganglia jointed by paired longitudinal connective on the ventral side .

• Three ganglia lie in the thorax , and six in the abdomen

• The nervous system of cockroach is spread throughout the body

• The head holds a bit of a nervous system while the rest is situated along the ventral part of its body

Reproductive system of cockroach ; •Male•Female

Male • It consist of a pair of vasa deferentia , an

ejaculatory duct , a utricular gland , a phallic gland , male genital apertures and external genitalia .

• A testis gives rise to single narrow tube from its posterior end called vas deferens .

• The two vasa deferentia run backwardly inwardly and downwardly they meet in the seventh or eight segment and open into an ejaculatory duct .

• The union is covered over by a large white mushroom shaped utricular gland present in 7th and 8th segments .

• The glands possesses three types of tubules- • Peripheral • Central • Seminal • The seminal tubules are bulbous in outline ,

they are also called seminal vesicles .• The phallic or conglobate glands lies below

the ejaculatory duct and utricular glands .

female • It is made up of ovaries • A pair of oviduct • A vagina • Female genital opening• Brood pouch • Gonapophyses or phallomeres

• A pair of spermathecae• A pair of colleterial glands.

dfg

Thank

you!By,Arya