To which of the following categories did the first formed cells of the primitive earth belong?
In the reducing environment of primitive Earth, large molecules such as amino acids and nucleic acids were formed from simple molecules. Under the influence of UV light and electrical discharges, polymers such as proteins and nucleic acids were formed. These in turn, formed the first cellular forms of life. Since the surface of Earth was continuously bombarded with UV rays, life on the surface was impossible. Hence, the first life adapted to exist deep in the ocean and derived energy from the chemicals on Earth. Hence, they were anaerobic chemotrophs. Many of them were also extremophiles, surviving under extreme conditions.