Evolution — BIOLOGY STD 12 Science — Question

1. Azoic era

Explanation:

An eon is the largest timespan in the geological timeline. An eon is subdivided into eras.

The Azoic Era was the oldest and long-lasting stage in the development of earth. There was no evidence of life in this era.

The Azoic era is the era when origin of the continental shelf occurred.

The continental shelf (Pangaea) was formed by the silica rich granite rocks of less density.