Munguva pfupi yapfuura, cytologists (cell biologists) vakafunga kuti chromosomes ndiyo yaive nhaka. Pakati pa1910 na1915, Thomas Hunt Morgan ne "Drosophilists" mu fly lab yake vakagadzira pfungwa mbiri idzi - zvese zvine nharo - mu "Mendelian-chromosome theory" yekugara nhaka. Vakaverenga huwandu hwezviitiko zvehukama hwehutano uye vakafungidzira kuti majini anogara pa chromosomes kunge ari pabhuruu; ivo vakafungidzira kutsanangura kuyambuka kwepamusoro uye kuvaka kweiyo genetic ma ma maps yeDogophila melanophila, iyo yakave modhi yakashandiswa zvakanyanya muMendel's basa. Kuburikidza ne1920s, nyanzvi dzezvirwere (cell biologists) dzakapa pfungwa yekuti chromosomes ndiyo yaive nhaka nhaka. Kuburikidza ne1930s, Fisher Hunt Morgan ne "Drosophilists" mu fly lab yake vakagadzira pfungwa nyowani yekushanduka kwevanhu, iyo yaingoonekwa nehunyanzvi hwekuita hunhu hwevanhu hunowanikwa nehunyanzvi hwekuita hunhu hwevanhu.
makromosome