Which type of blood cell is primarily responsible for the immune response?

• A. Eosinophil
• B. Erythrocyte
• C. Platelet
• D. Lymphocyte

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the role of each type of blood cell listed in the problem. Eosinophils are a type of white blood cell involved in combating parasitic infections and allergic reactions. Erythrocytes, or red blood cells, are responsible for transporting oxygen and carbon dioxide. Platelets are involved in blood clotting and wound repair.
2. Step 2: Recognize that the immune response is primarily mediated by white blood cells, also known as leukocytes. Among these, lymphocytes play a central role in adaptive immunity, which includes the production of antibodies and the activation of immune cells.
3. Step 3: Learn about the two main types of lymphocytes: B cells and T cells. B cells are responsible for producing antibodies, while T cells help in directly attacking infected cells and coordinating the immune response.
4. Step 4: Compare the functions of lymphocytes with the other blood cells listed in the problem. Eosinophils, while part of the immune system, are specialized for specific tasks like fighting parasites, and erythrocytes and platelets are not directly involved in immune defense.
5. Step 5: Conclude that lymphocytes are the blood cells primarily responsible for the immune response, as they are integral to both humoral and cell-mediated immunity.