Q. No.Griffith co-injected the heat-killed S and live R strains of Pneumococcus bacterium into the mice and much to his surprise the mice developed pneumonia and died. He concluded that:
I:
Live R was transformed into Live S strain as he was able to isolate Live S strain from the blood of the infected mice.
II:
Bacterial transformation is a stable and heritable change as the culture of bacteria isolated from dead mice was unable to infect other mice.
1.
Both I and II are correct
2.
Only I is correct
3.
Only II is correct
4.
Both I and II are incorrect
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
The radius of the double helix of B-DNA [Watson and Crick model] is approximately:
| 1. | 1.0 nm | 2. | 2.0 nm |
| 3. | 0.34 nm | 4. | 3.4 nm |
An RNA primer is essential for DNA synthesis carried out by DNA polymerase III. This is because, to synthesize DNA, DNA polymerase III requires:
| 1. | A free 3’ – PO4 group |
| 2. | A free 5’ – PO4 group |
| 3. | A free 3’ – OH group |
| 4. | A free 5’ – OH group |
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
Which of the following possible modes of replication was eliminated by Meselson and Stahl based on the finding after one generation of replication of the bacterium?
| 1. | Dispersive | 2. | Semi-conservative |
| 3. | Conservative | 4. | Both 1 and 3 |
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
The mRNA codon GUG codes for:
| 1. | Valine | 2. | Glutamic acid |
| 3. | Tryptophan | 4. | Formylated methionine |
What defines the template and coding strand of DNA for transcription?
1. Presence of the structural gene in a transcription unit
2. The core RNA polymerase enzyme
3. Presence of the promoter in a transcription unit
4. Presence of 3’ – 5’ TAC codon on the DNA template
In eukaryotes, RNA polymerase III transcribes:
| 1. | hnRNA, snRNAs and 5.8S RNA |
| 2. | tRNA, 5.8S RNA and snRNAs |
| 3. | tRNA, 5SrRNA and snRNAs |
| 4. | rRNAs – 28S, 18S and 5S |
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
Identify the incorrect statement:
| 1. | The DNA of the bacteriophage ϕ X 174 has 5386 nucleotides. |
| 2. | Bacteriophage lambda DNA has 48502 base pairs. |
| 3. | The DNA of Escherichia coli has 4.6 X 103 base pairs. |
| 4. | Haploid content of human DNA is 3.3 X 109 base pairs. |
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
In a DNA strand, two nucleotides are linked through a ___________ linkage to form a dinucleotide.
1. 3’ – 5’ phosphodiester bond
2. 5’ – 3’ phosphodiester bond
3. 1’ N-glycosidic bond
4. Two or three hydrogen bonds
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
The bacterial promotor sequence usually found at the -10 position (ten base pairs upstream of the transcription start site) is:
1. TTGACA
2. TAGACA
3. TATAAT
4. TATTAT
© 2025 GoodEd Technologies Pvt. Ltd.