Question

In dragons the allele for purple skin, P, is dominant over the allele for gray skin, and the allele for fire-breathing, F, is dominant over the allele for smoke-breathing. A purple, fire-breathing dragon and a gray, smoke-breathing dragon have 15 baby dragons. Three of the baby dragons have purple skin and breathe fire, four have gray skin and breathe smoke, five have purple skin and breathe smoke, and three have gray skin and breathe fire. What are the most likely genotypes of the parent dragons? Note, by convention, all alleles of a single gene are written together. For example AaBB and not ABaB. Please enter your genotypes per convention.

Answer 1

Answer:

PpFf and ppff

Explanation:

Gray skin and smoke breathing are recessive traits so to get expressed their recessive alleles should be present in two copies. Thus the parent with gray skin and smoke breathing traits has the genotype ppff.

Parent with purple skin and fire breathing trait can be PPFF, PpFF, PPFf or PpFf. Since they are dominant traits, only one allele is enough to produce the phenotype. However the resultant progeny has all type of trait combinations present. Along with the dominant variants, recessive variants can also be observed. Recessive genotype progeny will only occur when one of the parents is heterozygous since it receives one recessive allele from the homozygous recessive parent and other recessive allele from the heterozygous parent.

Thus, parent with dominant traits has the genotype PpFf.