Question

Immunity in our body is of two types: (i) Innate immunity and (ii) acquired immunity. Innate immunity is a non-specific defence mechanism, whereas acquired immunity is pathogen-specific; it is called specific immunity too. Acquired immunity is characterised by memory. Antibodies are specific to antigens and there are different types of antibodies produced in our body: they are IgA, IgE, IgG, IgC, and IgM. It shows primary response when it encounters the pathogen for the first time and secondary response during the subsequent encounters with the same antigen/pathogen. Name the two types of specialised cells which carry out the primary and secondary immune response.

Hint:

In organ transplants, immune rejection occurs when the recipient's immune system recognizes the donor tissue as foreign due to differences in MHC molecules. Cell-mediated immunity, involving T-cells, plays a key role in this process.

Answer 1

The two types of specialised cells which carry out the primary and secondary immune response: 
1. B-cells (B lymphocytes): These cells are responsible for the production of antibodies during both the primary and secondary immune responses. The primary response occurs when the body encounters the pathogen for the first time, and the secondary response occurs during subsequent encounters with the same pathogen.
2. T-cells (T lymphocytes): These cells assist in the immune response by either helping B-cells produce antibodies (Helper T-cells) or directly killing infected cells (Cytotoxic T-cells).