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
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 |
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 |
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 |
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. |
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
Replication in prokaryotes differs from replication in eukaryotes for which of the following reasons?
| 1. | Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not. |
| 2. | Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. |
| 3. | The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes. |
| 4. | Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not. |
Consider the following two statements:
| I: | During transcription, the template strand is read in a 3'-to-5' direction. |
| II: | During transcription, an RNA is transcribed in the 5'-to-3' direction. |
The correct statements is/are:
| 1. | I only | 2. | II Only |
| 3. | I and II | 4. | None |
Identify the correct statements from the given statements and choose the correct option:
| I: | Both prokaryotic and eukaryotic mRNAs have a 5' cap. |
| II: | Only prokaryotic mRNAs are polyadenylated at the 3' end. |
| III: | In prokaryotes, transcription is coupled to translation. |
| IV: | In eukaryotes, RNA splicing occurs after the mRNA is transported into the cytoplasm. |
| V: | RNA splicing requires the formation of a spliceosome. |
| VI: | Both prokaryotic and eukaryotic mRNAs are synthesized by RNA polymerase. |
| 1. | III, V, and VI only |
| 2. | II, III, V, and VI only |
| 3. | I, III, V, and VI only |
| 4. | I, III, IV, V, and VI only |
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