What two components make up blood?

• A. Water and plasma
• B. Platelets and plasma
• C. Plasma and formed elements
• D. Serum and plasma

Answer: (C)

The two main components of blood are plasma and formed elements. Plasma is the pale, yellow fluid that makes up most of the blood’s volume and carries water, dissolved proteins (like albumin, globulins, and fibrinogen), electrolytes, nutrients, hormones, and wastes. The formed elements are the living parts suspended in plasma and include red blood cells, which carry oxygen; white blood cells, which defend against infection; and platelets, which aid in clotting. Together, these two components account for the structure and function of blood.

Other options omit essential parts: water alone is just a solvent within plasma and does not represent the cellular portion; platelets with plasma would miss the majority of formed elements (red and white blood cells); serum plus plasma would exclude clotting factors and doesn’t describe blood as a whole.