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.
Three groups ofaquatic organisms include plankton, nekton, and benthos. Plankton are the organisms that float near the surface of the water. Two typesof plankton are microscopic plants called phytoplankton, and micro-scopic animals called zooplankton. Phytoplankton produce most ofthe food for an aquatic ecosystem. Nekton are free-swimming organ-isms, such as fish, turtles, and whales.