(i) Functions of Epithelial Tissue: 

(a) These protect the underlying tissues from mechanical and chemical injuries, dehydration and infection. 

(b) It act as selective barriers. 

(c) Surface epithelia produce skeletal structures like scales, feathers, hair, nails, claws, horns, hoofs etc. 

(d) Ciliated epithelia moves mucus or other fluids in the ducts, they line. 

(ii) Functions of Connective Tissues: 

(a) They primarily join one tissue to another in the organs. 

(b) Skeletal connective tissues like bone and cartilages, form a supporting framework for the body. 

(c) Adipose tissues acts as shock absorber around some organs, such as eye balls and kidneys. 

(d) Fluid connective tissue, like blood and lymph, carry materials from one part to another in the body.

(iii) Functions of Muscular Tissues: 

(a) They are involved in the movements of the body parts and locomotion of the organism. 

(b) They are responsible for the heart-beat, production of sound and peristalsis in tubular viscera. 

(c) They support the bones and other structure. 

(d) They play an important role in parturition (child birth).