Give one reason why (a) The blood is called connective tissue ?
(b) Muscles contain contractile proteins ? (c) Muscles of heart are involuntary ?

Explanation

(a) Blood has loosely spaced cells embedded in an intercellular fluid matrix. It acts as linking and supporting material which connects other tissues and organs of the body.
(b) The contractile proteins help in contraction and relaxation of muscles to cause movement.
(c) Muscles of heart perform contraction and relaxation throughout the life. Without tiring . They can not stopped or start according to our wish.