When a long-period comet is farthest from the sun in its orbit, which features of the comet exist? select all that apply.
a. coma
b. gas tail
c. nucleus
d. dust trail

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