This answer to the question above is a grade B answer.
Unicellular algae occur more frequently in water, especially in the plankton. Phytoplankton is the population of organisms that float freely consists mainly of single-celled algae. In addition, algae found in moist soil or on the surface of wet stone and wood. The live algae with fungi in low.
Unfortunately, the latest studies confirm a really dramatic. Phytoplankton, that billions of microscopic algae that form the basis of ocean food chain disappears with terrifying speed. Which means that the process "dead" seas and oceans is already irreversible, and the future does not sound good at all either for the human race.
As a marine/estuarine ecologist, I was always astonished by the shapes of diatoms that I collected from various water bodies. The diatoms, when studied under a scanning electron microscope (SEM), would take us to a different world of shapes and patterns. Here is a short scientific note on their shape and pattern.
Plankton is the mass of tiny organisms that drifts at or near the surface of oceans, lakes, and other bodies of water. The word plankton comes from a Greek word that means wandering. Some planktonic organisms can swim, but they cannot swim strongly enough to avoid being carried about by water currents.