PATHOLOGY

Detailed explanation-1: -clonal selection: An hypothesis which states that an individual lymphocyte (specifically, a B cell) expresses receptors specific to the distinct antigen, determined before the antibody ever encounters the antigen. Binding of Ag to a cell activates the cell, causing a proliferation of clone daughter cells.

Detailed explanation-2: -Clonal selection is a process by which the body produces B and T cells to respond to infections. These cells each have unique receptors that allow them to identify specific pathogens.

Detailed explanation-3: -After antigen presentation, selected lymphocytes undergo clonal expansion because they have the needed antigen receptor. Clonal selection may explain why memory cells can initiate secondary immune responses more quickly than the primary immune response, due to increased binding affinity from clonal expansion.

Detailed explanation-4: -The clonal selection theory proposes that antigen selects lymphocytes for activation from a population of cells precommitted to produce specific antibody. Implicit in this theory is that antibody-forming cells are monospecific and express cell-surface receptors capable of binding foreign antigens.

Detailed explanation-5: -Definition. The proliferation of B-lymphocytes and T-lymphocytes activated by clonal selection in order to produce a clone of identical cells. This enables the body to have sufficient numbers of antigen-specific lymphocytes to mount an effective immune response.