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.
Phytoplankton are tiny microscopic plants - algae - that form the base of the marine food chain. Phytoplankton is most abundant in colder waters where there is an abundance of nutrients. There are three types of algae: red, green and brown. Some algae in the ocean are very small and drift in the ocean water.