Ascientist tries to mate the two similar-looking fruit flies drosophila melanogaster and drosophila simulans. but he finds that they are unable to produce viable offspring. what kind of evolutionary barrier could this be?

Which of the following matches the organisms described with the correct domain? a. archaea--multicellular, eukaryotic organisms that do not have cell walls b. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sources c. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycan d. bacteria--unicellular, eukaryotic organisms that always lack cell walls