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.
Diatoms, dinoflagellates and microflagellates form the bottom of the aquatic food chain. Numbers of phytoplankton in an ocean might be so concentrated that they affect the color of the water and tint the water brown, green or red. Phytoplankton provide a necessary part of the aquatic food chain.