Compare and contrast the characteristics of B and T lymphocytes.

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College Answer

A structured response was required for this question. Candidates were expected to mention the origin of the  cells, sites of differentiation (foetal liver, lymph nodes, bone marrow in early childhood for T lymphocytes and thymus for B lymphocytes), antigen receptors and what they bind with (highly specific IgM surface antibodies that bind with extracellualr antigens for T lymphocytes and surface receptors that bind to antigen presenting cells for B ymphocytes), type of activation cell, type of immunity (humoral for T lymphocytes, cell mediated for B lymphocytes), their functions and life span (T lymphocytes much shorter than B lymphocytes. Although some candidates found this question challenging, of those who passed it, most achieved a high score.