Question

First life on earth was?

• A. Cyanobacteria
• B. Chemoheterotrophs
• C. Autotrophs
• D. Photoautotrophs

Answer 1

The correct option is A Cyanobacteria

• The fact that the oldest known fossils from the Archaean rocks of western Australia are of cyanobacteria is a very strong proof of them being the oldest lifeform on the Earth.
• These fossils date back to 3.5 billion years and are found in rocks that are themselves 3.8 billion years old.
• These shreds of evidence support the theory stating that cyanobacteria are the oldest living lifeform son the Earth.
  
• So, the correct answer is 'Cyanobacteria'.