Produce a di-hybrid cross Punnett square to illustrate the story described in italics below:
A six-transmembrane G-protein coupled receptor which controls the ability to taste a particular bitter compound is encoded for by the PX27R52 gene on chromosome 5. A common recessive allele of PX27R52 produces a non-functional receptor. The father in this cross is heterozygous, he has one wild type allele and one non-functional allele. This means that he can taste PTC. The mother of this cross is homozygous recessive with two non-functional alleles, she cannot taste the bitter compound.
There are two known alleles of gene occupying a specific locus in the X chromosome. The gene in question codes for a transcription factor involved in digit development. The clinically relevant allele is dominant and gives rise to an additional but non-functioning little finger (polydactyly) on both hands.
The father is hemizygous for the causative variant and was born with polydactyly, the mother is homozygous wild type at the same locus and therefore has the wild type phenotype.
The PX27R52 gene and the gene causing polydactyly show no linkage.