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Assertion : The predominant site for co...

Assertion : The predominant site for control ofgene expression in prokaryotes is transcription initiation.
Reason : The activity of RNA polymerase is regulated by accessory proteins, which affect recognition of start sites.

A

If both assertion and reason are true and reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but reason is false

D

if both assertion and reason are false.

Text Solution

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**Step-by-Step Solution:** 1. **Understanding the Assertion**: The assertion states that the predominant site for the control of gene expression in prokaryotes is transcription initiation. This means that the process of starting transcription is where the regulation of gene expression primarily occurs in prokaryotic cells. 2. **Understanding the Reason**: The reason provided is that the activity of RNA polymerase is regulated by accessory proteins, which affect the recognition of start sites. This indicates that RNA polymerase, the enzyme responsible for synthesizing RNA from a DNA template, requires additional proteins to help it identify where to begin transcription. 3. **Linking Assertion and Reason**: In prokaryotes, transcription initiation is indeed the key point of control for gene expression. The activity of RNA polymerase at the promoter (the region of DNA where transcription begins) is influenced by these accessory proteins. These proteins can either enhance (activators) or inhibit (repressors) the ability of RNA polymerase to recognize the start site. 4. **Conclusion**: Since both the assertion and reason are true, and the reason accurately explains the assertion, we conclude that both statements are correct. Therefore, we can affirm that the assertion is supported by the reason given. 5. **Final Answer**: Both the assertion and reason are true, and the reason is the correct explanation of the assertion. ---
**Step-by-Step Solution:** 1. **Understanding the Assertion**: The assertion states that the predominant site for the control of gene expression in prokaryotes is transcription initiation. This means that the process of starting transcription is where the regulation of gene expression primarily occurs in prokaryotic cells. 2. **Understanding the Reason**: The reason provided is that the activity of RNA polymerase is regulated by accessory proteins, which affect the recognition of start sites. This indicates that RNA polymerase, the enzyme responsible for synthesizing RNA from a DNA template, requires additional proteins to help it identify where to begin transcription. 3. **Linking Assertion and Reason**: In prokaryotes, transcription initiation is indeed the key point of control for gene expression. The activity of RNA polymerase at the promoter (the region of DNA where transcription begins) is influenced by these accessory proteins. These proteins can either enhance (activators) or inhibit (repressors) the ability of RNA polymerase to recognize the start site. ...
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