Which of the following is NOT a required step in B and T lymphocyte maturation?
A)Proliferative expansion of precursor cells
B)Cell surface expression of complete antigen receptor complexes
C)Positive selection
D)Activation of precursors by foreign antigens
E)Pre-antigen receptor expression

Question

Quizplus · Accepted Answer

Foreign antigens are not likely to be present in the generative lymphoid organs where lymphocytes mature and thus are not involved in the process.Both B cell and T cell maturation include sequential steps,including cytokine-induced proliferation and expansion of immature precursors,somatic recombination of Ig heavy chain or T cell receptor (TCR)F1F1F1S1F1F1F10 chain genes,expression of F1F1F1S1F1F1F10 heavy chain or TCR F1F1F1S1F1F1F10 chain with a surrogate nonvariable partner to form a pre-Ig or pre-TCR,somatic recombination of Ig light chain or TCR F1F1F1S1F1F1F10 chain genes,expression of complete antigen receptors and associated signaling molecules,and positive selection by recognition of self antigens.

Which of the Following Is NOT a Required Step in B