Question

multiple choice question
the oldest known fossils are ____ years old and resemble formations made by ____.
o 2.5 billion; cyanobacteria
o 3.7 billion; green algae
o 2.5 billion; green algae
o 3.7 billion; cyanobacteria

Explanation:

The oldest known fossils are about 3.7 billion years old and are stromatolites which resemble formations made by cyanobacteria. Cyanobacteria are some of the earliest life - forms on Earth.

Answer:

D. 3.7 billion, cyanobacteria