Final answer:
The limitless diversity of immunoglobulin genes is contributed by hypermutation, random heavy and light chain reassortment, and somatic recombination.
Step-by-step explanation:
The correct answer is D. hypermutation, random heavy and light chain reassortment, and somatic recombination. These three processes contribute to the limitless diversity generated from a relatively fixed number of immunoglobulin genes.
Hypermutation occurs in the variable regions of the immunoglobulin genes, leading to the introduction of random mutations. This process allows for the generation of a wide range of antibody variants.
Random heavy and light chain reassortment involves the mixing and matching of different V, D, and J gene segments during the recombination process, resulting in the creation of unique antibody molecules.
Somatic recombination is the process by which the variable region gene segments are rearranged and combined to form the complete immunoglobulin gene. This process further contributes to the diversity of antibody molecules.