Which statement correctly differentiates white blood cells from platelets?

• A. White blood cells are nucleated cells involved in immune defense; platelets are anucleate and involved in clotting
• B. White blood cells are anucleate; platelets are nucleated
• C. White blood cells are acellular fragments; platelets are fully nucleated
• D. White blood cells carry oxygen; platelets carry carbon dioxide

Answer: (A)

The main idea is that white blood cells are true cells with nuclei that defend the body, while platelets are anucleate fragments that specialize in clotting. White blood cells contain a nucleus and various organelles, enabling them to perform immune functions such as phagocytosis, antigen presentation, and antibody production. Platelets come from megakaryocytes and are small cytoplasmic fragments lacking a nucleus; their primary role is hemostasis—adhering to injured vessels, forming a platelet plug, and releasing factors that promote coagulation. Because platelets are anucleate, they don’t carry out gene transcription and have limited protein synthesis compared with nucleated white blood cells, aligning with their shorter lifespan and focused function. This combination of nucleus presence and distinct roles explains the correct differentiation.