The process of activating photoreceptors by altering the photopigments is known as .

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

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

Both destructive and constructive, the natural event seen here, is important in destroying and creating landforms on earth. what is this event called? a) deposition b) flooding c) landslide d) sedimentation