Question

How many different ways can homologous recombination cause gene conversion?

A) two

B) one

C) four

D) three

Answer 1

Ans. Two types gene conversion occurs in homologous recombination.

Gene conversion is the process by which one DNA sequence such that the sequences become identical after the conversion event. Gene conversion can be either allelic , meaning that one allee of the same gene replace another allel or ectopic , meaning that are paralogous DNA sequence converts another.

Allelic gene conversion : occurs during meiosis when homologous recombination between heterozygotic sites result in a mismatch in a base pairing.

Non allelic or ectopic gene conversion : Recombination occurs not only during meiosis but also as an mechanism for repair of double strand breaks caused by DNA damage . These DSB (double strand breaks) are usually repair using the sisters chromatid if the broken duplex and not the homologous chromosome , so they would not result in allelic conversion . Recombination also occurs between at different genomic loci ( paralogous sequence)