A molecule that can act as a genetic material must fulfill all the following criteria except:
1. It should be able to generate its replica.
2. It should chemically and structurally be stable.
3. It should be able to express itself in the form of Medelian characters.
4. It should provide scope for rapid changes required for evolution.
On examining a sample of human DNA, it was found that it contains approximately 24 % thymine. Which of the following would be true based on this finding?
1. The amount of adenine in a similar sample of DNA from any human being will be approximately 24 %.
2. The amount of adenine in a similar sample of DNA from any living being will be approximately 24 %.
3. The amount of adenine in a similar sample of DNA from any eukaryotic cell will be approximately 24 %.
4. The amount of adenine in a similar sample of DNA from any mammal will be approximately 24 %.
If the sequence of nitrogen bases of the coding strand of DNA in a transcription unit is:
5' -ATGAATG-3',
the sequence of bases in its RNA transcript would be;
1. 5'-AUGAAUG-3'
2. 5'-UACUUAC-3'
3. 5'-CAUUCAU-3'
4. 5'-GUAAGUA-3'
The RNA polymerase holoenzyme transcribes:
1. the promoter, structural gene and the terminator region
2. the promoter and the terminator region
3. the structural gene and the terminator region
4. the structural gene only.
To initiate translation, the mRNA first binds to:
1. The smaller ribosomal sub-unit,
2. The larger ribosomal sub-unit
3. The whole ribosome
4. No such specificity exists.
In E.coli, the lac operon gets switched on when:
1. lactose is present and it binds to the repressor
2. repressor binds to operator
3. RNA polymerase binds to the operator
4. lactose is present and it binds to RNA polymerase
Deoxyribonucleotides in a ds DNA are held by:
I. Phosphodiester.
II. Hydrogen.
III. Ionic.
1. I and II only
2. I and III only
3. II and III only
4. I, II and III
All the following will not be applicable to DNA replication in prokaryotes except:
1. It begins at several places along the chromosome.
2. It begins at the origin and travels in both directions.
3. It begins at the origin and travels around the chromosome back to the origin.
4. It begins at a GC rich region of the chromosome.
Constitutive heterochromatin includes:
1. The Barr body.
2. A region of active gene expression.
3. Telomeres.
4. Both 1 and 2.
Proof reading, the error-correcting processes, first proposed by John Hopfield and Jacques Ninio, during DNA replication takes place by:
1. Endonuclease cleavage.
2. Exonuclease cleavage.
3. Methylation.
4. An induced-fit phenomenon.