Question

Match the following

X	Ribosome binding site	1	Enhance transcription
Y	Promoter	2	Shine Dalgarno Sequence
Z	Enhancer	3	Molecular Switches to turn on transcription

• A. X-2; Y-3; Z-1
• B. X-1; Y-2; Z-3
• C. X-3; Y-1; Z-2
• D. X-3; Y-2; Z-1

Hint:

• Ribosome Binding Site (RBS) Sequence on mRNA for ribosome attachment to start translation (e.g., Shine-Dalgarno in prokaryotes, Kozak sequence context in eukaryotes).
• Promoter DNA sequence where RNA polymerase binds to start transcription. Acts as a switch.
• Enhancer DNA sequence that binds activator proteins to increase transcription rate, can be distant from the gene.

Answer 1

The Correct Option is A

Let's match the terms with their descriptions:

• X. Ribosome binding site: This is a sequence on mRNA where the ribosome binds to initiate translation.
  • 2. Shine Dalgarno Sequence: This is the ribosome binding site in prokaryotic mRNA.
  So, X \(\rightarrow\) 2.
• Y. Promoter: A DNA sequence where RNA polymerase binds to initiate transcription. It controls the start of gene expression.
  • 3. Molecular Switches to turn on transcription: Promoters are key molecular switches that regulate the initiation (turning on/off or modulating the level) of transcription.
  So, Y \(\rightarrow\) 3.
• Z. Enhancer: A DNA sequence that can increase the rate of transcription of a gene. Enhancers can be located far from the gene they regulate and can function in either orientation. They are bound by activator proteins.
  • 1. Enhance transcription: This directly describes the function of an enhancer.
  So, Z \(\rightarrow\) 1.

The matching is X-2, Y-3, Z-1. This corresponds to option (a). \[ \boxed{\text{X-2; Y-3; Z-1}} \]