Answer:
Cyanobacteria
Explanation:
Cyanobacteria or blue-green algae became the first microbes to produce oxygen by photosynthesis
Answer:
Autotrophic Cyanobacteria.
Explanation:
Cyanobacteria or blue-green algae became the first microbes to produce oxygen by photosynthesis, perhaps as long ago as 3.5 billion years ago and certainly by 2.7 billion years ago.
