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.
Small plant (phytoplankton) and animal (zooplankton) species that spend some or all of their life in the sea surface. Many marine species are planktonic in their life stages (e.g. cod, Dungeness crab) and they are the basis of the marine food web providing food for such sepecies as whale sharks and blue whales.