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.
Answer/Explanation:
The replication of DNA is semi-conservative, as each new molecule of DNA inherits one of the parental strands each, and one new strand each. DNA is replicated using the enzyme DNA polymerase, which synthesises a new strand by adding nucleotides in a sequence through complementary base pairing with the template strand. This occurs before the mitosis stage of the cell cycle, where the cell divides. Before this cell division happens, the cell has to pass certain checkpoints controlled by enzymes which ensure environmental conditions are optimal for dividing, and that the new DNA is free from errors.