Special tissue present in heart is cardiac muscle, these have the following features

(i) Cardiac muscle fibres are supplied with both central and autonomic nervous system and are not under the control of animal will.

(ii) These muscles are immune to fatigue and show rhythmicity.

(iii) They have rich blood supply.

(iv) They possess the property of contraction even if isolated from the body completely, i.e., they are myogenic

The table given below summarises the structure, location and function of the epithelial tissue

Structure	Location	Functions
Simple squamous epithelium (pavement epithelium) Its composed of single layer of flat cells.	This epithelium is present in the terminal bronchioles and alveoli of the lungs, walls of Bowman's capsules and descending limb of loop of Henle. In the blood vessels and heart it is called endothelium. In coelom, it is called as mesothelium.	Protection, excretion gaseous exchange and secretion of coelomic fluid.
Simple cuboidal epithelium It is composed of short cube-shaped cells with round nuclei located in centre of the cells. The cells of cuboidal epithelium often form microvilli on their free surface.	This epithelium is present in the small ducts of salivary glands and pancreas, thyroid vesicles, part of membranous labyrinth, proximal and distal convoluted tubules of the nephrons of kidneys, ovaries, seminiferous tubules and ciliary bodies.	Protection, secretion absorption and excretion.
Simple columnar epithelium In this, the cells are elongated and placed side by side like column. The outer free surface of each cell is slightly broader. This epithelium contains goblet (or mucous) cells.	It lines the stomach, intestine, gall bladder and bile duct. It also forms the gastric glands, intestinal glands and pancreatic lobules.	Protection,sec retion and absorption.
Simple ciliated epithelium This is made of cell bearing numerous delicate hair like outgrowth, arising from basal granules. Mucous secreting goblet cells are also present in them	These are present in the respiratry tract and Fallopian tubes (oviducts), in certain parts of nephrons in the kidney.	Protection as well as movement of mucus, urine, eggs and cerebrospinal fluid in particular direction. with help of cilia
Compound stratified epithelium It has many layers of epithelial cells, the deepest layer made of cuboidal cells. It is of four types (i) Stratified squamous epithelium. (ii) Stratified cuboidal epithelium. (iii) Stratified columnar epithelium. (iv) Stratified ciliated columnar epithelium.	Occurs in the epidermis of skin of land vertebrates. Oral cavity, tongue, pharynx, eye lids and cornea of eyes. Covers the epiglottis, lines the larynx and upper part of palate.	It is found on dry surfaces and are subjected to wear and tear i.e., skin, nails. Protects, underlying structures of body.
Compound transitional epithelium It consists of 4 to 6 layers of cells. There is no germinative layer or basement membrane but shows mitosis. The inner most cells rest on under lying connective tissue.	It lines the larynx and upper part of the soft palate. It is present in renal pelvis, ureters, urinary bladder and part of the urethra.	It forms epidermis of fishes and many urodeles. It permits distention thus, urinary bladder can be stretched considerably without being damaged.

Common features of connective tissue are

(i) Connective tissue is the most abundent and widely distributed tissue of the body. It connect with tissue with organs and also provides support to various body structures in animals.

(ii) Connects tissue is developed from the embroyonic mesoderm.

(iii) Three components are majorly present in the connective tissue matrix, cells and fibres.

(iv) The extracellular matrix has nearly amorphous ground substance made of glycoproteins with associated monopolysaccharides. This ground substance may be liquid, gel or solid.

(v) The tissue has good amount of regenerative ability.

(vi) Functions of connective tissue include storage of energy, protection of organs and body's structural integrity.

	Bone	Cartilage
Type	Bones are either compact or spongy. Bones are classified into long, short, flat, irregular sesamoid and structural bones.	Hyaline cartilage, fibro cartilage and elastic cartilage
Function	Protect the body against the mechanical damage, assist in the movement of the body, provide a framework and shape for the body, store minerals and produce red blood and white blood cells.	Reduces friction at joints, supports the respiratory tract, acting as shock absorbers between weight bearing bones and maintaining the shape and flexibility of fleshy appendages.
Structure	Bones are made up of mostly of osteoblasts (progenitor cells), osteocyte (mature bone cell) and osteoclasts (large cells, that breakdown bone tissue for growth and repair). A bone is highly vascularised.	Cartilages comprise chondroblasts (precursor cells), chondrocytes and dense matrix of collagen and elastic fibres in which the mature chondrocytes are embedded, cartilage is vascular.
Location	Bones make up the majority of the axial and appendicular skeleton.	Cartilage is much softer, more pliable component that is mostly found in between joints of bones (articular cartilage).
Fibrous covering	Periosteum is rich in sensory nerve endings.	Cartilage is much softer, more pliable component that is mostly found in between joints of bones (articular cartilage). Perichondrium (but does not surround articular cartilage).

Mating in earthworm is a unique process, earthworm is a hermaphrodite organism. Breeding in earthworm takes place during rainy season and begins with copulation soon after maturation of the sperms.

The gametic exchange and the physiology reproduction during mating can described as below

(i) Earthworms are protandrous animal (i.e., maturation of sperm takes place much earlier then that of ova).

(ii) Mating process in earthworm occurs through cross-fertilisation.

(iii) The mating process involves exchange of sperms between the two worms.

(iv) Two individuals from adjacent burrows half emerge out and lie in contact with each other, and opposite gonadal opening exchange the packets of sperms called spermatophores.

(v) During the process, the skin encircling male pore, elevates a little to form a temporary papilla that fits like a penis into the opposite spermathecal pore to keep it open.

(vi) After filling of spermathecal, the copulating worm moves a bit to adjust another pair of spermathecae to face the male pores of the other. This is accomplished in about an hour's copulation.

(vii) Within the spermathecae, the sperms mostly remain in their diverticula and the ampulla is associated with the secretion of nutritive substances for the sperms.

(viii) The sperm and egg are passed into cocoon which is secreted by clitellar gland.

(ix) Fertilisation is therefore external and cross fertilisation.

The alimentary canal present in cockroach is divided into three regions that foregut, midgut and hindgut.

(i) Foregut includes mouth cavity, pharynx, oesophagus, crop and gizzard.

(ii) Mouth cavity is a small space, surrounded by mouth parts. Food is crushed and acted upon by the salivary secretion in mouth.

(iii) The mouth opens into a short tubular pharynx, leading towards the narrow tubular passage called oesophagus into a sac-like structure called crop which acts as a storage organ.

(iv) The crop is further followed by gizzard (proventriculus). Gizzard the structure composed of thick circular muscles and thick inner cuticle forming six highly chitinous plates called as teeth. It associated with the grinding and crushing of food particles. Entire forgut is lined by a thick cuticle.

(v) Midgut or mesentron is about one-third middle part of alimentry canal. The internal lining of midgut is an endodermal epithelium of columnal cells raised into several small villi like folds.

(vi) Anterior most part of midgut surrounding the stomadaeal valve is called cardia and finger like blind processess are called as enteric or hepatic caeca, present the junction of foregut and midgut.

(vii) A ring of yellow filamentous structures formed between the midgut and hindgut are called Malpighian tubules help in the removal of excretory products from haemolymph.

(viii) Hindgut is the remaining one-third posterior part of alimentary canal. It is relatively thicker than the midgut is lined by cuticle and ectodermal epithelium.

(ix) Hindgut is differentiated into three parts, i.e., anterior ileum, middle colon and posterior rectum. Ileum is short and relatively narrower and its cuticle bears minute spines. Colon is the longest, relatively thicker and a coiled part of hindgut. Rectum is a small and oval chamber that opens out through anus.