The codon for the amino acid doubles as the start codon

Methionine (AGU)

Explanation:

The codon for the amino acid Methionine (AGU) doubles as the start codon.

I remember this form my Biology class and learning about all of this.

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.