Molecular Biology

1.

1 point

The ribozyme involved in the formation of peptide bonds during the process of transcription is:

Peptidyl transferase

RNA polymerase III

primase

Tepoisomerase

2.

1 point

Which of the following is not regarded as post translational modification

Cleavage of proinsulin to produce insulin

Attachment of poly A tail and 3rd end

Attachment of carbohydrates in

Disulfide cross link formation

3.

1 point

RNA polymerase catalyses the process of:

Translation

Transcription

Reverse transcription

replication

4.

1 point

All of the following are directly involved in the process of protein synthesis except:

tRNA

mRNA

tRNA

RNA primer

5.

1 point

The incorrect statement concerning translation is:

It can be targeted by antimicrobial agents because prokaryotic and eukaryotic ribosomes are different

Secretory protiens are synthesized by free ribosomes in eukaryotic cells

Polyribosomes are seen during the processes

It is the synthesis of proteins from mRNA

6.

1 point

One tRNA for leucine can read two of the Leucine codons. This is possible due to:

Wobblephenomenon

Strict Watson and Crick base pairing

Modification of bases in tRNA

Degeneracy of genetic code

7.

1 point

Which of the following statement is best suited for histones?

They are found in high concentrations in ribosomes

They are covalently attached to DNA

They are basic proteins rich in lysine and/or arginine

They are large sized proteins

8.

1 point

Set of three consecutive bases coding for one specific amino acid in a protein are present on:

mRNA

rRNA

tRNA

Introns

9.

1 point

The repair mechanism involved in repairing the damaged DNA of
nucleotide segment is:

Photoreactivation of pyrimidine dimers

Base excision repair

Nucleotide excision repair

Mismatch repair

10.

1 point

Okazaki fragments are seen during the synthesis of:

mRNA

Peptide bonds

Leading strand of DNA

Lagging strand of DNA

11.

1 point

Which one of the following enzymes can join okazaki fragments in new DNA strand

DNA ligase

Helicases

Primase

DNA polymerase II

12.

1 point

Common lesions found in the DNA after exposure to ulraviolet light are:

Base deletions

Single strand breaks

Base excision

Thymine dimers

13.

1 point

Concerning restriction enzymes, the incorrect statement is:

EcoRI is a restriction enzyme

They are bacterial enzymes

They are artificially created by genetic engineering

They cut double stranded DNA at palindromic sequences

14.

1 point

mRNA undergoes all the following modifications except:

Splicing process

Supercoiling

Attachment of 7th Methyl Triphosphate at 5th end

Attachment of poly A tail at 3rd end

15.

1 point

Reverse transcriptase is an enzyme used by retroviruses that transcribes genetic information of the virus from:

RNA into protien

RNA into RNA

DNA into RNA

RNA into DNA

16.

1 point

Which one of the following is correct regarding the genetic code:

There are only 20 codons, one for each amino acid

Codons for the same amino acid differ in different species

One codon codes for more than one amino acids

AUG is the start codon

17.

1 point

Which of the following is not required in the polymerase chain reaction?

Taq DNA polymerase for elongation step

Primers and nucleotides

Denaturing the template DNA at high temperature

Bacteria for cloning the recombinant DNA

18.

1 point

Which of the following is untrue regarding DNA fingerprint:

Radio isotope labeled probes are used to detect the patterns of bands

It involves VNTR

This technique is used for synthesis of insulin for therapeutic purposes

It is unique for each individual

19.

1 point

During the splicing process of an mRNA precursor in a eukaryotic cell, the portions that are discarded are referred to as:

Exonss

Introns

Poly A tail

Duplicate genes

20.

1 point

Patients sufferring from Xeroderma pigmentosum are highly sucessptible for skin cancer. This disorder is cause due to mutation in the gene involved in:

Translation

Nucleotide-Excission repair mechanism

Replication

Transcription

21.

1 point

The true statement concerning euchromatin is:

It is always inactive

It is a transcriptionally active chromatin

At times condensed but at other times active

It is a metaphase chromosome

22.

1 point

DNA wrapped around histone octomer is:

Nucleosome

Promoter

Polysome

Heterchromatin

23.

1 point

Removal of signal sequence from the amino terminal of a newly synthesized protein is a

Mutation repair

transcription

Post translational modification

Post transcriptional

24.

1 point

Which one of the following is incorrect about DNA replication:

Replication is initiated at multiple origins in eukaryotes

Replication occurs during S phase of the cell cycle

DNA synthesis occurs from 3' to 5' direction

DNA polymeras III is the main enzye involved