ANSWER:
Cyanobacteria increased the 'levels of carbon dioxide' in the atmosphere is a false statement.
Step-by-step explanation:
- Cyanobacteria is in the shape of blue-green-algae increased the levels of oxygen.
- It is believed they were the first organism which were able to produce oxygen in the process of photosynthesis.
- They use carbon dioxide for photosynthesis and release oxygen.
- Cyanobacteria live in the seawater, so oxygen produced by photosynthesis first enters in to the water.