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Read the following statements for lac op...

Read the following statements for lac operon:
i. Each operon has its specific operator and specific repressor.
ii. The y gene codes permease, which increases the permeability of the cell to beta-galactosides.
iii. Regulation of lac operon can be visualized as regulation of enzyme synthesis by its substrate.
Select the option with the correct statements.

A

All statements are correct.

B

All statements are incorrect.

C

Only i is correct and ii & iii are incorrect.

D

Only i & ii are correct

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the lac operon, we need to evaluate each of the three statements provided and determine their correctness. ### Step-by-Step Solution: 1. **Understanding the Lac Operon**: The lac operon is a set of genes in E. coli that is responsible for the metabolism of lactose. It consists of structural genes (lacZ, lacY, and lacA), a promoter, and an operator. 2. **Evaluating Statement i**: - **Statement**: "Each operon has its specific operator and specific repressor." - **Analysis**: This statement is true. Each operon, including the lac operon, has a specific operator where the repressor binds to regulate gene expression. 3. **Evaluating Statement ii**: - **Statement**: "The y gene codes permease, which increases the permeability of the cell to beta-galactosides." - **Analysis**: This statement is also true. The lacY gene codes for permease, which facilitates the entry of lactose and other beta-galactosides into the cell. 4. **Evaluating Statement iii**: - **Statement**: "Regulation of lac operon can be visualized as regulation of enzyme synthesis by its substrate." - **Analysis**: This statement is true as well. The presence of lactose (the substrate) induces the expression of the genes in the lac operon, leading to the synthesis of enzymes necessary for lactose metabolism. 5. **Conclusion**: Since all three statements are correct, the correct option is the one that includes all three statements as true. ### Final Answer: All three statements (i, ii, iii) are correct. Therefore, the correct option is **A**.
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