Question

How do B-lymphocytes and T-lymphocytes recognize specific antigens?

Answer 1

Receptors.

Explanation:

B-cells have B-cell Receptors on their surfaces that can recognize million different types of antigens. A Naive B-cell has all the receptors on its surface. But once it comes in contact with an antigen, it differentiates to memory and plasma cells that exhibit only one type of receptor, antigenic specificity.

T-cells too have T-cell receptors that detect the antigen on the surface of the Antigen Presenting cells. The antigens are presented to the T-cells through a MHC-Antigen complex. The same methos of recognition and differentiation happens in T cell too.