Question

What is the role of the lac operon in gene regulation?

• A. Protein synthesis
• B. Transcription control
• C. Cell division
• D. DNA replication

Hint:

The lac operon is a classic example of gene regulation in prokaryotes. It helps the cell respond to the availability of lactose by controlling gene transcription.

Answer 1

The Correct Option is B

Step 1: Understanding the lac operon.
The lac operon is a segment of DNA involved in the regulation of gene expression in prokaryotes, specifically in E. coli. It is responsible for controlling the transcription of genes involved in the metabolism of lactose.
Step 2: Analysis of options.

• (A) Protein synthesis: Incorrect. While the lac operon indirectly affects protein synthesis, its primary role is in controlling the transcription of genes involved in lactose metabolism, not in protein synthesis itself.
• (B) Transcription control: Correct. The lac operon regulates the transcription of genes necessary for the breakdown of lactose in the cell. It controls whether certain genes are expressed or not in response to the presence or absence of lactose.
• (C) Cell division: Incorrect. The lac operon does not directly control cell division. Its role is in gene regulation, not cell division.
• (D) DNA replication: Incorrect. The lac operon does not have a direct role in DNA replication; its function is in transcription regulation, not replication.

Step 3: Conclusion.
The lac operon primarily controls the transcription of genes involved in lactose metabolism in response to environmental conditions. Final Answer:} Transcription control.