Give one reason for the following statements:
$(a)$ Blood is called a connective tissue.
$(b)$ Muscles are able to contract and relax to bring about movements.
$(c)$ Muscles of the heart are called involuntary muscles.

(N/A) Blood is considered a connective tissue because it connects different body organs by transporting gases,digested food,hormones,and waste materials throughout the body.
$(b)$ Muscles contain special proteins known as contractile proteins (actin and myosin),which contract and relax to facilitate movement.
$(c)$ Muscles of the heart are called involuntary muscles because they undergo rhythmic contraction and relaxation throughout life without conscious control and without getting fatigued.