(a) Nictitating Membrane It protects the eye from water and any other damaging matter by covering the eye ball of forg.

(b) Tympanum It is a present on each side of frog head and is involved in the hearing process.

(c) Copulatory Pad These pads are present in the limbs of the male frog and helps in copulation by holding the female during its sexual activity.

(a) Simple Columnar Epithelium This epithelium lines the stomach, intestine, gall bladder etc. It forms goustric and intestinal glands, where it has a secretory role and is called as glandular epithelium. In intestinal mucosa, this epithelium has microvilli which increase the absorptive surface area and is called brush bordered columnar epithelium.

(b) Stratified Epithelium These are made up of more than one layer of epithelial cells (also called compound epithelium). They are the only cells of the deepest layer and rest on the basement membrane they cover the surface where constant wear and tear take place. They mainly function as a protective epithelium.

(c) Connective Tissue It is the tissue which connects different tissues or organs and provides support to various structures of animal body. These tissues are mesodermal in origin and consist of living cells and extra cellular matrix, e.g., blood is a fluid or vascular connective tissue.

Segmentation is the serial repetition of similar body parts along with the length of an animal. The body of animals can be truely segmented or pseudo/false segmented. True segmentation is found in annelids, arthropods and some chordates. In this, there is a linear repetition of body parts and each repeated unit is called somite (metamere). In earthworms, the successive somites are essentially similar but they are dissimilar in different body regions of a crayfish or insect. Metamerism is conspicuous both externally and internally in annelids. Pseudosegmentation is seen when body is divided into number of pseudosegments which are independent of each other. Each segment is able to perform all the vital function of body. Body grows by the addition of new segments from the anterior end, e.g., tapeworm.

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.