Question

In which one of the following does antibody formation take place?

• A. RBCs
• B. Blood platelets
• C. Blood plasma
• D. Donnan's membrane

Hint:

Think about which blood component is liquid and carries the gamma globulin proteins.

Answer 1

The Correct Option is C

Step 1: Understanding the Question.
The question asks where in the blood antibodies are actually formed and found.

Step 2: Key Concept.
Antibodies, also called immunoglobulins, are protein molecules made by plasma cells, which are B lymphocytes that have matured after meeting an antigen. Once made, these antibody proteins are released into the liquid part of the blood, the blood plasma, where they travel as part of the gamma globulin fraction of plasma proteins.

Step 3: Detailed Explanation.
RBCs, or red blood cells, carry oxygen using haemoglobin. In humans, mature RBCs have no nucleus and cannot make any protein, so they cannot form antibodies.
Blood platelets are small cell fragments that help blood clot by forming a plug at an injury site. They also lack a nucleus and play no part in making antibodies.
Donnan's membrane is not a body part at all. It refers to the Donnan equilibrium, a physical chemistry idea about how charged particles distribute across a semipermeable membrane. It is not a site where antibodies are produced.
Blood plasma is where the antibodies made by plasma cells end up dissolved, forming the gamma globulin part of plasma proteins that fights infection.

Step 4: Final Answer.
Antibody formation, in the sense of where antibodies are found circulating in the body, takes place in blood plasma.