Question

1. Immune system (select the BEST CORRECT statement)

   		When activated by an antigen, B lymphocytes undergo clonal expansion and give rise to both memory cells and plasma cells.
   		Secreted antibody molecules are derived from B cell receptors through an alternative splicing mechanism that removes the receptor’s transmembrane domain.
   		Although B cell receptors are expressed on the surface of B lymphocytes, they function in the tethering and trapping of foreign antigens and are not linked to intracellular signaling cascades.
   		All of the above are correct
   		Only (a) and (b) are correct

Answer 1

Only option A and B sre correct

A, When activated by an antigen, B lymphocytes undergo clonal expansion and give rise to both memory cells and plasma cells.

Explanation-

B well act as antigen presenting cells , it express antigen to bind with MHC II molecule to Th cells. TH cell upon activation released cytokines which activate B cell . This activated B cell converted in to plasma cell which secret antibody. And memory cell which mediate secondary immune response in case if antigen re enter in to the body

B, Secreted antibody molecules are derived from B cell receptors through an alternative splicing mechanism that removes the receptor’s transmembrane domain

Explanation

Upon activation due to alternative splicing soluble antibodies are form which mediate humoral immune response. Different between soluble and transmembrane antibody is presence of transmembrane part which is absent in soluble antibody