clonal selection and clonal expansion

Question 1

define clonal selection

Answer 1

the identification of one specific B cell and one specific T cell which has a complementary receptor to bind to the antigen of the pathogen

Question 2

outline the process of clonal selection

Answer 2

1) the antigen presenting macrophage must identify one specific B and T cell with complementary receptors to the antigen
2) after a period of time the antigen will bind out the complementary receptor in the membrane of one of the specific B or T cells and the cell becomes activated = clonal selection
3) the selected cell then divided by mitosis producing millions of identical clones= clonal expansion

Question 3

outline the process of differentiation after clonal expansion in the humoral response

Answer 3

1) clonal expansion of the specific B lymphocyte occurs by mitosis
2) the B lymphocyte differentiates into either a B plasma cell of a B memory cells
3) the B plasma cell releases antibodies with specific binding sites to the antigen allowing neutralisation and agglutination
4) B memory cells do not fight infection but stay in the body and respond if the pathogen enters the body again in the future= secondary immune response

Question 4

outline the process of differentiation in the cell mediated response