In eukaryotic cells, where does transcription take place?

• A. On the ribosome
• B. In the cytoplasm
• C. In the nucleus
• D. In the mitochondria

Answer: (C)

Transcription is the process of copying DNA into RNA, and in eukaryotic cells this happens inside the nucleus, where the DNA is housed. RNA polymerase binds to genes in the chromatin and builds the RNA transcript, which is then processed (capping, splicing, polyadenylation) before being exported to the cytoplasm for translation on ribosomes. In contrast, translation occurs on ribosomes in the cytoplasm, so that’s not where transcription happens. The cytoplasm itself lacks the DNA template needed for transcription of nuclear genes. Mitochondria do carry out transcription for their own genes, but the primary location for transcribing nuclear genes in a eukaryotic cell is the nucleus.