Question

the only nitrogen base found in rna but not dna is

Explanation:

DNA has nitrogen - bases adenine (A), guanine (G), cytosine (C), and thymine (T). RNA has adenine (A), guanine (G), cytosine (C), and uracil (U). So, uracil is the nitrogen base found in RNA but not in DNA.

Answer:

Uracil