Question

1. what are stromatolites?

inorganic polymers
group of eukaryotes
colony of cyanobacteria
bubbles with a membrane

Explanation:

Stromatolites are layered structures formed by the growth of cyanobacteria (blue - green algae). Cyanobacteria are prokaryotes, not eukaryotes. Inorganic polymers do not describe stromatolites. Bubbles with a membrane are not related to the definition of stromatolites.

Answer:

colony of cyanobacteria