Findings in ancient rocks indicate cells first appeared
A) about 4.5 billion years ago.
B) about 3.5 billion years ago.
C) about 2 billion years ago.
D) before rocks were formed.
E) before water arrived on Earth.

Question

Quizplus · Accepted Answer

The findings in ancient rocks indicate that cells first appeared about 3.5 billion years ago. This is based on the discovery of fossilized remains of bacteria-like organisms in rocks that date back to this time period. While the origin of life on Earth is still a subject of scientific debate, these findings suggest that simple forms of life were already present on Earth at least 3.5 billion years ago.

Findings in Ancient Rocks Indicate Cells First Appeared