Of the Following Groups, Which Have Been in Existence the Longest

Question

Of the following groups, which have been in existence the longest?
A) multicellular animals
B) cyanobacteria
C) gastropods
D) green algae

Accepted Answer

Cyanobacteria, also known as blue-green algae, are the oldest known group of photosynthetic organisms, with fossils dating back over 3 billion years ago. The other listed groups (multicellular animals, gastropods, and green algae) evolved much later in Earth's history.