A True breeding Wild type fly was crossed with a True breeding Mutant fly to produce a Heterozygous F1. An F1 female was then crossed to a Test male. The results of this cross are as follows: cn vg 4202; cn 458; rd 4258; rd vg 482; cn rd 28; Wild Type 276; vg 32; cn rd vg 264. Which Phenotypes represent the Parentals i. e., the non- Cross Over Phenotypes from the F1 generation

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.