A millibar is a unit of pressure which is most commonly seen in the context of meteorology, where atmospheric pressure is sometimes given in millibars. As the name would suggest, a millibar is equal to one thousandth of a bar.
User: The microscopic organisms at the base of the marine food chain are known as A. plant life. B. terrestrial animals. C. primitive life. D. phytoplankton. Weegy: The microscopic organisms at the base of the marine food chain are known as Phytoplankton. User: In addition to being necessary for respiration, _______ also provides UV radiation protection. A. water B. hydrogen C. oxygen D. carbon dioxide.
Within the plankton, holoplankton spend their entire life cycle as plankton (e.g. most algae, copepods, salps, and some jellyfish).By contrast, meroplankton are only planktic for part of their lives (usually the larval stage), and then graduate to either a nektic or benthic (sea floor) existence. Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores. 2  Zooplankton (from Greek zoon, or animal), small protozoans or metazoans (e.g. crustaceans and other animals) that feed on other plankton and telonemia.