Question

Which of the following is wrongly matched pair?

• A. Repressor $\rightarrow$ Protein coded by regulatory gene of operon
• B. Operon $\rightarrow$ Promoter, Structural genes, Operator
• C. Translation $\rightarrow$ Polymerisation of amino acids and polypeptide chain formation
• D. Transcription $\rightarrow$ Attachment of amino acid to a specific t-RNA

Hint:

Transcription = DNA to RNA. Translation = RNA to Protein. Charging of tRNA occurs before translation and is neither transcription nor translation.

Answer 1

The Correct Option is D

Concept: Gene expression occurs through two major processes:
• Transcription: Formation of RNA from DNA template.
• Translation: Formation of protein from mRNA. Amino acid attachment to tRNA is a separate process known as aminoacylation or charging of tRNA.

Step 1: Examine Option (A). A regulatory gene synthesizes a repressor protein. The repressor binds to the operator region and regulates transcription. Thus Option (A) is correctly matched.

Step 2: Examine Option (B). An operon consists of:
• Promoter
• Operator
• Structural genes Thus Option (B) is correctly matched.

Step 3: Examine Option (C). Translation involves linking amino acids through peptide bonds to produce a polypeptide chain. Thus Option (C) is correctly matched.

Step 4: Examine Option (D). Attachment of amino acid to a specific tRNA is not transcription. It is called charging of tRNA or aminoacylation. Transcription is the synthesis of RNA from DNA. Therefore this pair is incorrectly matched.

Step 5: Final conclusion. Option (D) is wrongly matched.