Question

The PCR primer ‘D7S820’ is used to amplify the D7S820 locus. Using this gel below, determine whether each person (M1, P1, P2, C1) is homozygous or heterozygous at this locus. Also determine the size of each person’s amplicons. Using this gel, you can determine paternity. M1 is the mother. C1 is the child. Is P1 or P2 the father of C1? Explain how you made this determination. If you were actually determining paternity, would you use one PCR primer? Why?

Answer 1

1) M1 is heterozygous since it contains 2 bands, which means that it contains one recessive and one dominant allele

P1 is homozygous for this locus, since it contains a single band or is known to be homozygous for the locus or gene.

P2 is hetozygous for this locus because two bands appear in which each band represents one allele for the gene.

ChildC contains two gel bands, representing two alleles and is therefore heterozygous

P1 is the father of the child C1, if we look at the gel, each father shows a similar band, one coinciding with the mother and the second with the father p1

As for the paternity study, the PCR test is not useful, since it provides asymmetric results, thus only one strand information will be provided, and because the DNA is double-stranded, a more complete study is required.: