MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Cell Biology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In bacteria, mRNAs bound to small metabolites are called ______________ |
| A. | euchromatin |
| B. | riboswitches |
| C. | heterochromatin |
| D. | nucleosome |
| Answer» C. heterochromatin | |
| 2. |
Which of the following acts as a co-repressor in tryptophan operon? |
| A. | tryptophan |
| B. | tyrosine |
| C. | glucose |
| D. | lactose |
| Answer» B. tyrosine | |
| 3. |
The lac operon is under positive control, a phenomenon called _________________ |
| A. | regulation |
| B. | mutation |
| C. | lactose-effect |
| D. | glucose-effect |
| Answer» E. | |
| 4. |
Which of the following acts as an inducer in the lac operon? |
| A. | glucose |
| B. | tryptophan |
| C. | lactose |
| D. | galactose |
| Answer» D. galactose | |
| 5. |
The lac operon consists of ____ structural genes. |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 6. |
The capability of the repressor to bind the operator depends upon _____________ |
| A. | pH |
| B. | conformation |
| C. | temperature |
| D. | moisture |
| Answer» C. temperature | |
| 7. |
The repressor protein is encoded by _________________ |
| A. | regulatory gene |
| B. | structural gene |
| C. | transfer-DNA |
| D. | ribosomal-RNA |
| Answer» B. structural gene | |
| 8. |
Which is a DNA-binding protein? |
| A. | repressor |
| B. | operator |
| C. | luciferase |
| D. | thymidine |
| Answer» B. operator | |
| 9. |
The structural genes in an operon lie adjacent to one another. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
In a bacterial operon, which is located downstream of the structural genes? |
| A. | operator |
| B. | inducer |
| C. | promoter |
| D. | regulatory gene |
| Answer» E. | |
| 11. |
When was the operation mechanism of a bacterial operon first elucidated? |
| A. | 1961 |
| B. | 1971 |
| C. | 1981 |
| D. | 1991 |
| Answer» B. 1971 | |
| 12. |
Enzymes of __________________________ are clustered together in a bacterial operon. |
| A. | metabolic pathway |
| B. | transcription |
| C. | transfusion |
| D. | transformation |
| Answer» B. transcription | |
| 13. |
Under minimal conditions, the cell has fewer than 5 copies of enzyme -galactosidase. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 14. |
The first step in catabolism of lactose by the bacteria is ________________ of a linkage bond. |
| A. | hydrolysis |
| B. | oxidation |
| C. | reduction |
| D. | alkylation |
| Answer» B. oxidation | |
| 15. |
Lactose can be a nutrient source for bacteria, it is a _____________________ |
| A. | monosaccharide |
| B. | lipid |
| C. | disaccharide |
| D. | polysaccharide |
| Answer» D. polysaccharide | |