Answer:
I'm pretty sure the answer is A.
Explanation:
RNA is transcribed in the nucleus; after processing, it is transported to the cytoplasm and translated by the ribosome.
<h3><u>Answer and Explanation</u>;</h3>
- Purines: Heterocyclic rings are synthesized one atom at a time, first atom attached to ribose phosphate (source is PRPP) and then all the other atoms are added .
- Pyrimidines: Common intermediate, orotate, synthesized first, then orotate is attached to ribose phosphate (source is PRPP or 5-Phosphoribosyl-1-pyrophosphate).