The "oxygen crisis" occurred around
A) 2 billion years ago
B) 3.5 billion years ago
C) 2.5 billion years ago
D) 4 billion years ago

Name: The "oxygen crisis" occurred around A) 2 billion years ago B) 3.5 billion years ago C) 2.5 billion years ago D) 4 billion years ago
Brand: Quizplus
Rating: 4.8 (33 reviews)

Question

Quizplus · Accepted Answer

The "oxygen crisis," also known as the Great Oxidation Event, occurred around 2 billion years ago when oxygen levels significantly increased in Earth's atmosphere.

The "Oxygen Crisis" Occurred Around