Algae

The term “algae” has long been used to denote all organisms that produce O2 as a product of photosynthesis. One major subgroup of these organisms, the blue-green bacteria, or cyanobacteria – are prokaryotic and no longer are termed algae. This classification is reserved exclusively for photosynthetic eukaryotic organisms. All algae contain chlorophyll in the photosynthetic membrane of their subcellular chloroplasts. Many algal species are unicellular micro organisms. Other algaes may form extremely large multicellular structures. Kelps of brown algae sometimes are several hundred meters in length.

Related studies
Science research on these micro spieces.
Microbial uni and multi cell organisms.
Knowledge on fungi.
Slime study as microbial.