In which one of the following, antibody formations takes place?

Antibodies, also known as immunoglobulins, are specialized glycoproteins produced by plasma cells, which are fully differentiated B-lymphocytes [t3][t6]. These plasma cells synthesize and secrete thousands of antibody molecules per second into the circulatory system to neutralize pathogens [t5][t7]. While red blood cells (RBCs) are responsible for oxygen transport [c2] and platelets are involved in blood clotting, they do not produce antibodies. Antibodies constitute approximately 20% of the total protein found in blood plasma [t3]. Consequently, the blood plasma serves as the primary medium where these antibodies are found and circulate throughout the body to provide humoral immunity [t2][t6]. Donnan’s membrane refers to an electrochemical equilibrium phenomenon across a semi-permeable membrane and is unrelated to protein synthesis or immune response [t8]. Therefore, antibody formation and presence are fundamentally associated with the plasma component of blood.

Sources

1. [1] https://www.ncbi.nlm.nih.gov/books/NBK513460/
2. [2] https://www.britannica.com/science/plasma-cell
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.7 > p. 91
4. [4] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/plasma-protein
5. [5] https://www.sciencedirect.com/science/chapter/edited-volume/pii/B9780128179277000028