Question

Select the 2 correct statements that describe cyanobacteria. (1 point)
• Cyanobacteria were the first photosynthesizing organisms
• Cyanobacteria have complex cells containing a nucleus
- • Cyanobacteria lived in the ocean
• Cyanobacteria decreased the levels of oxygen in the atmosphere

Answer 1

The two correct statements that describe cyanobacteria are:

1. **Cyanobacteria were the first photosynthesizing organisms.**
2. **Cyanobacteria lived in the ocean.**

Cyanobacteria do not have complex cells containing a nucleus (they are prokaryotic), and they actually increased the levels of oxygen in the atmosphere through photosynthesis, not decreased them.