For one person to produce over a million different antibody molecules could not possibly require over a million different genes. Instead, this variability is accounted for by which processes?
A)alternative splicing of exons after transcription
B)increased rate of mutation in the RNA molecules
C)DNA rearrangements followed by alternative splicing of the transcripts
D)DNA rearrangements in the thymus cells
E)crossing-over between the light and heavy chains of each antibody molecule during meiosis I

Question

Quizplus · Accepted Answer

The variability in antibody molecules is primarily accounted for by DNA rearrangements followed by alternative splicing of the transcripts. During B-cell development, segments of DNA are recombined to create unique variable regions of the antibody molecules. This process is called V(D)J recombination and can generate millions of different combinations. Alternative splicing of the transcripts from these rearranged genes can also contribute to diversity. Therefore, neither alternative splicing of exons after transcription nor increased rate of mutation in RNA molecules can create such vast variability. DNA rearrangements in thymus cells and crossing-over during meiosis are not involved in the generation of antibody diversity.

For One Person to Produce Over a Million Different Antibody