Answer:
Replication is the process of formation of daughter DNA molecules by DNA polymerase enzyme using the existing DNA strands as a template. Since DNA and the enzymatic machinery for replication and transcription are present in the nucleus, the processes of replication and transcription occur in the nucleus only. Transcription is the process by which the DNA molecule makes an RNA molecule using enzyme RNA polymerase and other proteins. The mRNA is then used to generate proteins by a process called translation which occurs in the cytoplasm. Transcription occurs in the nucleus because DNA cannot leave the nucleus.