(i) Prevents food from entering the trachea during swallowing.   (ii) Transfers impulses from inner ear to brain.   (iii) Initiates cell division in animal cells.   (iv) Helps to change the focal length of the eye lens.   (v) Transports oxygen to the cells of the human body.   (vi) Helps to increase the volume of the chest cavity lengthwise.   (vii) Transports manufactured food from leaves to other parts of the plant.   (viii) Acts as bearer of heredity units.