Given what we know, we can confirm that the significant increase in oxygen in the Earth's atmosphere 2 to 2.5 billion years ago is due to cyanobacteria.
<h3>What are cyanobacteria?</h3>
These are tiny bacterial organisms. They were amongst the first organisms to use photosynthesis to sustain life. The sudden boom of cyanobacteria accounts for the rapid increase in oxygen given that they will use carbon dioxide to produce sugar through photosynthesis, expelling oxygen in the process.
Therefore, we can confirm that the significant increase in oxygen in the Earth's atmosphere 2 to 2.5 billion years ago is due to cyanobacteria.
To learn more about cyanobacteria visit:
brainly.com/question/832454?referrer=searchResults
Answer:
C. Hypothesis
Explanation:
Hypothesis is a proposed explanation for a certain occurrence and when the explanation is conclusive, then it becomes a theory.
Allan already had a heart attack and can try to prevent another one by changing the diet, exercising, or even quit smoking, but there are non-modifiable risks such as age, sex and generic heritage, so If Allan is over 40 years old, male or comes from a family with heart diseases, Allan needs to be extra careful because those factors cannot be changed no matter how the way of life is changed.
