Vietnam or Thailand? Vote for the TOP Country of the Week!
Want to type faster? Practice with a typing test or have fun with typing games!
Updated: October 7, 2026
According to T. H. Morgan, it is simply due to the fact that the determinants for such characters are situated in the sex-chromosome. Morgan, however, also states that a case of true sexual dimorphism arose as a mutation in his cultures of Drosphilia. The character was eosin colour in the eye instead of the red colour of the eye in the original fly.