Question

Choose the correct labels for I, II and III from the options given below:

• A. I - Opsonisation, II - Fc receptors, III - Phagocytosis
• B. I - Antibodies, II - TCR, III - Opsonisation
• C. I - Opsonisation, II - TCR, III - Endocytosis
• D. I - Phagocytosis, II - Fc receptor, III - Opsonisation

Answer 1

The correct option is A

I - Opsonisation, II - Fc receptors, III - Phagocytosis

IgG molecules bind to the antigens on the pathogen. This makes the pathogen available for attack by phagocytic cells of our immune system. Fc receptors are present on phagocytic cells which bind the Fc region of the antibody. Thus the antibody enables phagocytic cells to recognise pathogens and mediates their phagocytosis. This process of marking the pathogen followed by phagocytosis, is termed as opsonisation.