Amain function of the leaf petiole is a. to extend the leaf blade away from the stem so the blade can collect sufficient sunlight. b. to keep the leaf away from the secondary meristem of the stem. c. to produce pollen. d. none of the above

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