An indicator for a protein is added to a solution
that contains protein and to a solution that does
not contain protein. state one way, other than the
presence or absence of protein, that the two
solutions may differ after the indicator has been
added to both. [1]

the answer is d.) homologous; have mammary glands

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.