Is oxygen an element of nitrogenous base?

Answer 1

Oxygen is simply an element. Nitrogen is another element. They can combine to make a variety of compounds, but no element is "based" on another.

Answer 2

No, oxygen is not an element of a nitrogenous base. Nitrogenous bases are classified as adenine, guanine, cytosine, thymine, and uracil, which contain nitrogen atoms but no oxygen in the ring structure. Oxygen is found in other molecules like sugars and phosphates that make up DNA and RNA.