Which of the following mechanisms is NOT involved in the generation of antibody diversity?
A) Recombination with excision of DNA between a V gene sequence and a J sequence B) Splicing out of RNA sequences between a J region and a C region C) Somatic hypermutation D) Non-homologous end joining and DNA repair E) Transposition
A) involves a multisubunit enzyme. B) preferentially repairs genes that are being actively transcribed. C) involves making nicks on either side of a DNA lesion. D) uses helicase, polymerase and ligase to repair the DNA. E) all of the above.
The SOS response to DNA damage in bacteria is error-prone because:
A) it uses DNA polymerase that lacks 5' exonuclease activity. B) it is an inducible system. C) the polymerases used lack 3' exonuclease activity. D) more than one polymerase can be used to repair the damage. E) it is stimulated by ultraviolet light that causes mutations.