The taking in of water and dissolved minerals and nutrients across cell membranes. Contrast with ingestion . Most anaerobic organisms are bacteria or archaeans . Any organism that is able to manufacture its own food.
Most plants are autotrophs, as are many protists and bacteria .
Contrast with consumer . Autotrophs may be photoautotrophic , using light energy to manufacture food, or chemoautotrophic , using chemical energy. Organisms that live on the bottom of the ocean are called benthic organisms. They are not free-floating like pelagic organisms are. Layer of vegetation elevated above the ground, usually of tree braches and epiphytes.