Question

The term cyanobacteria can be broken down into parts. Cyan- means

“greenish blue,” because cyanobacteria are often blue-green in color. Not too long ago, cyanobacteria were known as blue-green algae. Why do you think they were considered algae?

Answer 1

because they are photosynthetic and aquatic, cyanobacteria was often called "blue-green algae".