Final answer:
Blood is classified as a connective tissue because it has a matrix called plasma and connects different parts of the body. It contains red blood cells and white blood cells.
Step-by-step explanation:
Blood is classified as a connective tissue because it has a matrix and connects various parts of the body. It contains living cell types such as red blood cells (erythrocytes) and white blood cells (leukocytes). The matrix of blood is called plasma, which is a fluid portion of whole blood.