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.

Identify the incorrect statement regarding structure of DNA:
1. Pitch is 3.4nm and 10 base pairs.
2. The two strands are antiparallel.
3. Each pair of nucleotides is held together by three hydrogen bonds.
4. The diameter of the molecule is a uniform 2nm.

In which models of DNA replication In this model the two parental DNA strands are back together after replication has occurred?
1. Conservative model.
2. Semiconservative model.
3. Dispersive model.
4. Destructive model.

If a bacterial cell were to contain 4 nucleoids per cell, the number of copies of the bacterial chromosome present in each cell will most likely be:
1. 1
2. 2
3. 3
4. 4