Select the 2 correct statements that describe cyanobacteria

Question

A. Cyanobacteria decreased the levels of oxygen in the atmosphere
B. Cyanobacteria have complex cells containing a nucleus
C. Cyanobacteria lived in the ocean
D. Cyanobacteria were the first photosynthesizing organisms

Answer 1

The two correct statements that describe cyanobacteria are:

C. Cyanobacteria lived in the ocean
D. Cyanobacteria were the first photosynthesizing organisms

Cyanobacteria are known for their role in producing oxygen through photosynthesis and are often considered to be some of the earliest photosynthetic organisms on Earth. They can be found in various aquatic environments, including oceans.