Question

Which one of the following is wrongly matched?
A. Transcription- Writing information from DNA to t-RNA.
B. Translation- Using information in m RNA to make protein.
C. Repressor protein- Binds to an operator to stop enzyme synthesis.
D. Operon- Structural genes, Operator and Promoter.

Answer 1

Hint: Translation is the process of translating sequence of a messenger (mRNA) molecule to the amino acid sequence during synthesis of protein.

Complete step by step answer:
Transcription occurs by following steps:
1. Transcription factors with RNA polymerase bind to the promoter DNA.
2. RNA polymerase- separates the two strands of the DNA helix by breaking hydrogen bonds between complementary DNA nucleotides and adds RNA nucleotides that are complementary to one strand of DNA nucleotides.
3. The hydrogen bonds of RNA-DNA helix break, RNA strands (newly synthesized) become free.
4. The DNA stretch transcribed into a RNA molecule is called a transcription unit and encodes one gene.
5. If that gene encodes a protein, transcription gives messenger RNA which in turn serves as a template for the synthesis of protein by translation.
Steps of translation:
1. Initiation: First tRNA attached at the start codon.
2. Elongation: tRNA transfers an amino acid to tRNA of the next codon. Ribosome moves to the next mRNA codon and this process continues to create the amino acid chain.
3. Termination: Ribosomes release polypeptide, after the stop codon is reached.

Option A is the correct answer.

Note: Transcription is the writing information from DNA to mRNA.
Repressor protein binds to the gene’s promoter region to stop the production of messenger RNA. Operon is the functional unit of genetic regulation.