Q. No.In a strand of nucleic acid, two nucleotides are linked together by:
1. 3’ – 5’ phosphodiester bond
2. 5’ – 3’ phosphodiester bond
3. 2’ – 5’ phosphodiester bond
4. 3’ – 1’ phosphodiester bond
1. 3’ – 5’ phosphodiester bond
2. 5’ – 3’ phosphodiester bond
3. 2’ – 5’ phosphodiester bond
4. 3’ – 1’ phosphodiester bond
In Griffith's experiment, which of the following bacterial strains was capable of causing pneumonia in mice?
| 1. | Live R |
| 2. | Bacteria strain with polysaccharide coat |
| 3. | Heat Killed S |
| 4. | Live R with capsule and Heat Killed S |
What facilitates the opening of the helix during the elongation step of transcription?
| 1. | RNA polymerase | 2. | Helicase |
| 3. | Topoisomerase | 4. | Gyrase |
The repressor of the lac operon is:
| 1. | Lactose itself | 2. | A steroid |
| 3. | Synthesized constitutively | 4. | A product of structural gene |
The base pairing in a double stranded DNA is correctly described as:
| 1. | Similar | 2. | Identical |
| 3. | Complementary | 4. | Synergistic |
In a transcription unit, RNA polymerase binds to:
| 1. | Ori | 2. | Promoter |
| 3. | Operator | 4. | Structural gene |
The distance between a base pair in the DNA double helix is approximately:
| 1. | 2.0 nm | 2. | 0.34 nm |
| 3. | 20 nm | 4. | 3.4 nm |
In some viruses, the flow of genetic information is from RNA to DNA. These viruses are:
| 1. | Reverse transcriptases | 2. | Reoviruses |
| 3. | Ribozymes | 4. | Retroviruses |
In a transcription unit, with respect to structural genes, the promoter is located:
| 1. | Upstream and 5’ | 2. | Upstream and 3’ |
| 3. | Downstream and 5’ | 3. | Downstream and 3’ |
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