Question

Respiration requires $O_2$. How did the first cells on the earth manage to survive in an atmosphere that lacked$O_2$?

Answer 1

First cells on the earth:

The first cells on the earth were anaerboes who managed to survive in an atmosphere that lacked $O_2$.

Anaerobes:

$\bullet$ Anaerobes are the organisms that can survive in an environment that lacks O2.

$\bullet$ They obtain energy (ATP) from anaerobic respiration by the breakdown of inorganic substances.

Final answer: Anaerobic respiration