In which cellular compartment does DNA replication occur?

In which cellular compartment does DNA replication occur?

• A. Cytoplasm
• B. Nucleolus
• C. Mitochondria
• D. Nucleus

Answer: (D)

DNA replication occurs where the chromosomes are housed and replicated, which in eukaryotic cells is the nucleus. The nuclear envelope keeps the genome distinct from the cytoplasm while replication machinery (like DNA polymerases, helicases, and primases) duplicates the linear chromosomes during S phase. The nucleolus is mainly for ribosomal RNA transcription and ribosome assembly, not genome replication. The cytoplasm is involved in many metabolic processes, but nuclear DNA replication specifically happens within the nucleus. Mitochondria do replicate their own circular DNA inside the mitochondria, a separate compartment from the nuclear genome. Therefore, the nucleus is the correct site for replication of the nuclear genome.

DNA replication occurs where the chromosomes are housed and replicated, which in eukaryotic cells is the nucleus. The nuclear envelope keeps the genome distinct from the cytoplasm while replication machinery (like DNA polymerases, helicases, and primases) duplicates the linear chromosomes during S phase. The nucleolus is mainly for ribosomal RNA transcription and ribosome assembly, not genome replication. The cytoplasm is involved in many metabolic processes, but nuclear DNA replication specifically happens within the nucleus. Mitochondria do replicate their own circular DNA inside the mitochondria, a separate compartment from the nuclear genome. Therefore, the nucleus is the correct site for replication of the nuclear genome.