Answer:
Uracil (U) is found in RNA only. Thymine (T) is found in DNA only.
Step-by-step explanation:
DNA has the nitrogenous bases adenine (A), thymine (T), guanine (G), and cytosine (C). On the other hand, RNA has the nitrogenous bases adenine (A), uracil (U), guanine (G), and cytosine (C).
Thus, only RNA has uracil (U) and only DNA has thymine (T).