Breeding a purple male with a bronze hen produces male chicks Males looking indiable but actually split to purple and bronze, purple gene on one chromosome and bronze gene on another chromosome. The female chicks have one purple gene on one Z chromosome ( that is the only Z chromosome it possess ) and the other is a sex chromosome W which does not carry any genes. Hence it is a purple. If we have to say that the hen is " a purple split bronze" ?? Which chromosome the bronze gene sits on ???? Is it the Z chromosome ?.. In other words , Is there a binding site on the Z chromosome for the bronze genetic nucleotide to fit in, besides purple, By the by neither of these are pattern genes. and both are color mutations from India blue though.