Question

Question 5 3 p Although each B cell carries two alleles encoding the lg heavy chain and two alleles for each of two light chains genes, only one heavy chain and only one light chain are ultimately expressed per cell. True False Question 6 3 pts Multiple factors that increase antigen receptor diversity also increase formation of non-productive alleles. Which of the following would generate a non-productive allele? Select all correct. Net addition of nucleotides that are a multiples of 3 at the junctions Junctional diversity that generates a receptor that bind self antigens Net addition of nucleotides that are not multiples of 3 at the junctions Generation of a stop codon at the junctions

Answer 1

1) Yes this is true, this phenomenon is called allelic exclusion. Only one allele for a heavy chain and one allele for a light chain. The other alleles are not transcribed.

Answer True.

2) A non productive allele of VDJ recombination is an allele which produces an antigen non-reactive antibody.

A self antigen will not bind to any foreign antigens, therefore it is a non- productive allele

A non 3 multiple will cause a frame shift shifting the entire frame of the transcript producing a defunct allele. This is because codons are 3 nucleotides. This is the same reason why multiples of 3 additions wont do as much damage.

The stop codons will also stop transcription.

Therefore the answer is Option 2,3,4