Which is the best definition of directional selection?

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

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

Urban areas use energy than rural areas, mostly because so many more people live there. a) solar power b) more; in total c) less; in total d) an electric furnace