I le va o le 1910 ma le 1915, Thomas Hunt Morgan ma le "Drosophilists" i lona lele lab forged nei manatu e lua - uma feteenai - i le "Mendelian-chromosome teori" o le tuufaasolo. Latou quantified le mea moni o le tuufaasolo tuufaasolo ma postulated e genes nonofo i chromosomes pei i luga o beads; latou hypothesized faamatalaina sopoia i luga o le matua ma fausia le genetic o le melanocytes Drosophila, lea na avea ma se faataitaiga faaaogaina moni lava i le galuega a Mendel. vave ina ua mavae, cytologists (selu biologists) fuafuaina o chromosomes sa le meafaitino tuufaasolo. i le va o le 1910 ma le 1915, Thomas Hunt Morgan ma le "Drosophilists" i lona lele lab forged nei manatu e lua - uma feteenai - i le "Mendelian-chromosome teori" o le tuufaasolo.
o le chromosome