Question

Assertion :Replication and transcription occur in the nucleus but translation occurs in the cytoplasm. Reason: mRNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acids are available for protein synthesis.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Replication is the process of formation of daughter DNA molecules by DNA polymerase enzyme using the existing DNA strands as template. Transcription is the process of RNA synthesis using DNA template strand which is carried out by RNA polymerase; any of two DNA strands can serve as template. Since DNA and the enzymatic machinery for replication and transcription are present in nucleus, the processes of replication and transcription occur in nucleus only. The primary transcript, formed by the process of transcription, is then modified via post transcriptional modifications into mature mRNA which is then transported to cytoplasm through nuclear pores where ribosomes (the site for protein synthesis) and amino acids (monomer for protein synthesis present in amino acid pool of cytoplasm) are present to carry out the process of translation i.e. synthesis of polypeptides by polymerization of amino acids on ribosomes using the mRNA triplets as template. Thus, Assertion is correct and Reason is correct explanation for it. Correct answer is A.