Before cyanobacteria appeared, Earth’s atmosphere was composed of water vapor, carbon dioxide, nitrogen and other gases. Where did these gases come from?

Question

They were released by the atmosphere.

They were released by the biosphere.

They were released by the geosphere.

They were released by the hydrosphere.

Answer 1

The correct answer is: They were released by the geosphere.

The gases in Earth's early atmosphere, such as water vapor, carbon dioxide, and nitrogen, primarily originated from volcanic outgassing and other geological processes from the geosphere. These processes included volcanic eruptions that released gases trapped in the Earth's interior into the atmosphere.