Which term describes blood as plasma, red cells, white cells, and platelets?

• A. Plasma
• B. Blood
• C. Hemoglobin
• D. Coagulation

Answer: (B)

Blood is the circulating tissue that includes both the liquid part, plasma, and the formed elements—red blood cells, white blood cells, and platelets. This combination of plasma plus cells is what we call blood. Plasma serves as the fluid matrix carrying nutrients, hormones, and waste. The formed elements include erythrocytes (red cells) that transport oxygen, leukocytes (white cells) that defend against infection, and platelets that help with clotting. Hemoglobin is a protein inside red blood cells responsible for oxygen binding, not the whole blood, and coagulation refers to the clotting process, not the entire blood composition. So the term that describes blood as containing plasma along with red cells, white cells, and platelets is blood.