Serum is the straw-colored part of the blood. Which option best describes serum?

• A. Plasma
• B. Straw-Colored Part of the Blood
• C. White Blood Cells
• D. Platelets

Answer: (B)

Serum is the liquid part of blood that remains after it has clotted and the clotting factors are removed. It is pale straw-colored, which is why it’s described as straw-colored. This distinguishes it from plasma, which is the liquid from anticoagulated blood and still contains clotting factors like fibrinogen. White blood cells and platelets are cellular components, not the liquid serum. So the option that describes serum as the straw-colored part of the blood best matches its appearance and composition.