Question

A single B lymphocyte produces an immunoglobulin of only one specificity. A given B cell has two sets of chromosomes, one set from each parent, so theoretically, immunoglobulin genes located on both chromosomes could synthesize immunoglobulin molecules. This does not occur. Immunoglobulin chains are coded for by only one set of genes, either from the maternal or the paternal chromosome. For example, the heavy chain may be coded for by genes on the paternal chromosome and the light chain by genes on the maternal chromosome. What is this phenomenon called?

Molecular mimicry
Gene conversion
Allelic exclusion
Transgenesis
Antigenic shift

Answer 1

Allelic exclusion is the phenomenon where only one set of genes from either the maternal or paternal chromosome is used to code for immunoglobulin chains.

Step-by-step explanation:

The phenomenon described, where only one set of genes from either the maternal or paternal chromosome is used to code for immunoglobulin chains, is called allelic exclusion. During the maturation of B cells, the V, D, and J regions of the immunoglobulin genes undergo rearrangement, resulting in the synthesis of diverse immunoglobulin antibodies. This process occurs in response to foreign substances called antigens.

However, only one set of genes, either from the maternal or paternal chromosome, is utilized for the coding of immunoglobulin chains, ensuring the production of immunoglobulins of only one specificity.