Question

You are studying humans with sticky ear wax, a recessive trait. You don’t know what gene causes sticky ear wax. You assay children of parents known to be heterozygous for the sticky ear wax trait and for various common SSRs. Most of the SSR alleles assort randomly from the sticky ear wax trait, but one of them gives the following results: Sticky, short form only: 25 children Not sticky, long and short form: 50 children Not sticky, long form only: 25 children What can you conclude from these results?

Answer 1

Ans. Ear wax trait is encoded by ABCC11 gene,ATP-binding cassette,sub-family C (CFTR/MRP),member 11 in humans.

As per literature there is SSR /SNP in ABCC11 gene of chromosome16 at the base position 538 of either a guanine or adenine controls for multiple distinct phenotypes,thus subsequently codes for glycine and arginine in the genes protein products. Dominant inheritance of the GG or GA genotype is observed while the AA genotype is recessive.

But to give proper cross representing f1 and f2 generation for the given question, data is not sufficient as value for sticky short form only is not given, hence cannot properly conclude from insufficient data.

From the as such gives the idea that though there is SSR but characters are following mendelian inheritance for dihybrid crosses...but need correct values to confirm the same.