Phytoplanktons refers to the marine algae that are responsible for the production of food on which the aquatic species are dependent on. They are the major producers of freshwater ecosystems. This freshwater includes rivers, streams, ponds, and lakes. They are mostly dominated in the upper region of the water body, where they get the necessary amount of sunlight in order to carry out the process of photosynthesis. Some of the examples of phytoplanktons are cyanobacteria, algae, and diatoms.
The Proterozoic division of the geological time scale is an era of the Phanerozoic eon. The Proterozoic division began 2.5 billion years ago and ended 542.0 million years ago.
