Summary
Photosynthetic bacteria that oxygenated Earth's atmosphere billions of years ago.
In depth
They invented oxygenic photosynthesis about 2.4 billion years ago, causing the Great Oxidation Event. Stromatolites are layered structures built by them. Some fix nitrogen in heterocysts. Chloroplasts evolved from them.
Blooms can produce toxins.
Cyanobacteria include unicellular and filamentous forms. Heterocysts protect nitrogenase. Toxic blooms in warm, nutrient-rich waters harm animals.
Example: Prochlorococcus is among the smallest and most abundant photosynthesisers.
Frequently asked questions
What is Cyanobacteria?
Photosynthetic bacteria that oxygenated Earth's atmosphere billions of years ago.
Which area of biology covers Cyanobacteria, and how advanced is it?
Cyanobacteria is one of the 54 topics in Microbiology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Nitrogen-Fixing Bacteria, Pathogens, Bacteria.
Can you give an example of Cyanobacteria?
Spirulina is a cyanobacterium eaten as a supplement.
What should I learn before Cyanobacteria?
Work through the Beginner topics in Microbiology first, such as Microorganisms, Bacteria, Archaea, then return to Cyanobacteria. Intermediate topics assume the Beginner vocabulary.
What topics are related to Cyanobacteria?
The closest topics to Cyanobacteria are Nitrogen-Fixing Bacteria, Pathogens, Bacteria, Microorganisms. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cyanobacteria?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cyanobacteria. To practise the whole of Microbiology, use the Microbiology quiz.
How is Cyanobacteria different from Nitrogen-Fixing Bacteria?
Cyanobacteria: Photosynthetic bacteria that oxygenated Earth's atmosphere billions of years ago. Nitrogen-Fixing Bacteria: Rhizobium and others convert atmospheric nitrogen into ammonia for plants. Read both side by side and note what each one explains.
How should I study Cyanobacteria step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Nitrogen-Fixing Bacteria and explain the difference aloud. Finally, take the Microbiology quiz and come back to this page for any question you miss.