Explain why the response of third line of defence, both cellularand
antibody immunity, is specific in nature.

Presence of specific antigen receptors on the surface of Immunocompetent B and T cells make them to generate immune response against specific antigens only.

Explanation:

The cellular and antibody-mediated immune responses are specific in nature. This means these immune responses are generated for particular foreign molecules or antigens only. These immune responses include B and T lymphocytes. Before T cells leave the thymus or B cells leave the red bone marrow, they develop immunocompetence. Immunocompetence is the ability to carry out adaptive immune responses. During this process. B cells and T cells make distinctive proteins and insert them into their plasma membranes. Some of these proteins function as antigen receptors capable of recognizing specific antigens. This is why the B and T cell-mediated third line of defense are specific in nature.

For example, antibody-mediated immune responses generate the memory cells for most previously encountered antigens to ensure the generation of more rapid and vigorous response during any further encounter with the same antigen.

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

the answer is golgi apparatus