<prompt> Synthesis of an immunoglobulin in membrane bound or secretory form is determined by:One turn to two turn joining ruleClass switchingDifferential RNA processingAllelic exclusion  <response>: Ans. is c i.e., Differential RNA processing Ref: Kuby Immunolo 6the, p. 130 - 131 Differential RNA processing of a common primary transcript determines whether the secreted or membrane form of an immunoglobulin will be produced. Membrane bound or secreted form of immunoglobulin differs in the amino acid sequence of the heavy chain carboxyl terminal domains. 