Question

Cyanobacteria are bluish green in color because they contain what?

Answer 1

chlorophyll

Bacteria called cyanobacteria are very important. They are bluish green in color  see Figure below   because they contain chlorophyll. They make food through photosynthesis and release oxygen into the air. These bacteria were probably responsible for adding oxygen to the air on early Earth. This changed the planets atmosphere. It also changed the direction of evolution. Ancient cyanobacteria also may have evolved into the chloroplasts of plant cells.