What is/are the role(s) of deoxyribonucleoside
triphosphates during DNA replication?

A. Act as substrate.
B. Catalyse the polymerisation of ribonucleic acid.
C. Provide energy for polymerisation reaction.

1. A only

2. B only

3. A and B

4. A and C

The following diagram refers to the process of transcription in Eukaryotes. Identify A, B, C and D –

Choose the correct statements –
I. Binding of mRNA to the ribosome is loose and reversible.
II. The ribosome, which is composed of tRNA and proteins, consists of a small and large subunit.
III. Each of the 20 amino acids has a minimum of one specific tRNA molecule.
IV. tRNA^MET binds to the first codon (AUG) – this is called the START codon.
V. The second tRNA binds to the second codon so that their attached monosaccharides are next to each other.
VI. The newly formed polypeptide may undergo post-transcriptional modification.

1. I, III and IV
2. II, IV, VI
3. II, V and VI
4. I, V, VI.

By performing a series of experiments that showed the effect of R and S strains of Streptococcus pneumoniae on mice, Griffith concluded that

1. Protein digesting enzyme does not affect
      transformation.

2. DNA is more stable genetic material than RNA.

3. DNA replication is semi conservative.

4. Non-virulent bacteria were tranformed by heat killed
     virulent bacteria.

What will be the sequence of mRNA produced by the following stretch of DNA?

3' ATGCATGCATGCATG 5' TEMPLATE STRAND

5' TACGTACGTACGTAC 3' CODING STRAND

1. 3' AUGCAUGCAUGCAUG 5'

2. 5' UACGUACGUACGUAC 3'

3. 3' UACGUACGUACGUAC 5'

4. 5' AUGCAUGCAUGCAUG 3'

Which among the following characteristics confers
stability to the DNA helical structure?

i.  Presence of Uracil.

ii. Plane of one base pair stacking over the other in
    DNA helix.

iii. Left handed fashion coiling of DNA helix.

iv. Presence of hydrogen bonds.

1. i and ii

2. ii and iii

3. iii and iv

4. ii and iv

Which scientist experimentally proved that DNA is the sole genetic material in bacteriophage?

1. Beadle and Tatum

2. Messelson and Stahl

3. Hershey and Chase

4. Jacob and Monod

What initiation and termination factors are involved in transcription in prokaryotes?

1. $\mathrm{\sigma }$ $\mathrm{and}$ $\mathrm{\rho }$, respectively

2. $\mathrm{\alpha }$ $\mathrm{and}$ $\mathrm{\beta }$, respectively

3. $\mathrm{\beta }$ $\mathrm{and}$ $\mathrm{\gamma }$, respectively

4. $\mathrm{\alpha }$ $\mathrm{and}$ $\mathrm{\sigma }$, respectively

Amino acid sequence in protein synthesis is determined by sequence of  
1. rRNA
2. tRNA
3. mRNA
4. cDNA.

Read the following four statements (A-D):  
(A) In transcription, adenosine pairs with uracil.
(B) Regulation of lac operon by repressor is referred to as positive regulation.
(C) The human genome has approximately 50,000 genes.
(D) Haemophilia is a sex-linked recessive disease.
How many of the above statements are right ?
1. Two
2. Three
3. Four
4. One