DNA Transcription Location in Eukaryotic Cells

Steps:

• Recall that transcription is the process where DNA is copied into mRNA.
• Identify that in eukaryotic cells, DNA is housed in the nucleus.
• Note that transcription requires DNA as the template, so it happens where DNA is located.
• Confirm that post-transcription, mRNA exits the nucleus for translation elsewhere.

Why D is correct:

• Transcription occurs in the nucleus, where DNA is stored and protected by the nuclear envelope, as defined in eukaryotic cell biology.

Why the others are wrong:

• A: Ribosomes are sites for protein synthesis (translation), not DNA transcription.
• B: Cytoplasm lacks DNA; it's where translation occurs after mRNA export.
• C: Mitochondria have their own DNA for limited transcription, but main cellular transcription is nuclear.

Final answer: D