Answer: Nitrogen-fixing Bacteria
Explanation:
In the Nitrogen cycle, nitrogen fixing bacteria are very important in ensuring that plants get nitrogen to enable them grow and as animals have to eat plants, these bacteria are essential for our survival as well.
Plants are unable to use atmospheric nitrogen but nitrogen-fixing bacteria are able to synthesize ammonia from atmospheric nitrogen. They can then convert this to Nitrites and Nitrates which are more useful to plants and animals by extension.
