A Cross Was Made Between Homozygous Wild -Type Female Drosophila

Short Answer

A cross was made between homozygous wild -type female Drosophila and
yellow -bodied male Drosophila. All of the resulting offspring were phenotypically wild type. Offspring of the F2 generation had the following phenotypes:
Based on this information:
a() Is the mutant gene for yellow body behaving as a recessive or dominant gene?
b() Is the yellow locus on an autosome or on the X chromosome?