Answer:
Nucleus in eukaryotes, Cytosol in prokaryotes
Step-by-step explanation:
Transcription is the first process of protein synthesis involving the copying of the information in DNA into a RNA molecule.
In eukaryotic cells, DNA, which is the genetic material, is located in the nucleus. Eukaryotic cells have a true nucleus which houses the cell's DNA and directs protein synthesis, hence, it is just normal that this process of transcription occurs in the nucleus of eukaryotic cells.
However, prokaryotic cells possess a naked DNA i.e. not housed by a membrane-bound nucleus. The process of transcription and translation is coupled together i.e. The RNA transcript is translated while still being synthesized. Hence, this coupled process occurs in the cytoplasm