Answer: run off from land/rivers and phytoplankton blooms
Explanation:
Nitrogen, particularly as nitrate is easily leached from soil. Human agriculture relies on fertilisers with significant nitrate content that applied at levels higher than it can be used. The balance end up as runoff, much of which ends up in
It’s when an uncomplimentary base in double-stranded DNA is caused by spontaneous deamination of cytosine or adenine. Also mismatching during homologous recombination, or any errors in DNA replication.
