MCQOPTIONS
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MCQOPTIONS
This section includes 6 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the regulation of a lac operon by a repressor known as? |
| A. | Neutral regulation |
| B. | Positive regulation |
| C. | Mixed regulation |
| D. | Negative regulation |
| Answer» E. | |
| 2. |
Which of the following is the necessary condition for the entry of lactose into the cell? |
| A. | High level expression of lac operon |
| B. | Low level expression of lac operon |
| C. | Absence of lac operon in the cell |
| D. | Absence of proteins in the cell |
| Answer» C. Absence of lac operon in the cell | |
| 3. |
Which of the following is responsible for the switching on and off of the lac operon? |
| A. | Lactose |
| B. | Ethanol |
| C. | Malate |
| D. | Fructose |
| Answer» B. Ethanol | |
| 4. |
What does the structural gene (y) of a lac operon code for? |
| A. | β-galactosidase |
| B. | Transacetylase |
| C. | Permease |
| D. | Glucagon |
| Answer» D. Glucagon | |
| 5. |
How many structural genes are present in a lac operon? |
| A. | One |
| B. | Five |
| C. | Three |
| D. | Seven |
| Answer» D. Seven | |
| 6. |
Which polycistronic structural gene is regulated by a common promoter and regulatory gene? |
| A. | Trp operon |
| B. | Lac operon |
| C. | Ara operon |
| D. | His operon |
| Answer» C. Ara operon | |