The cloning step in PCR/sequencing analysis of microbial communities is necessary for

preventing contamination by outside DNA

separating the different rRNA gene sequences in the mixture

widely different than southern blotting

another name for southern blotting

Which of the statement is incorrect for anchored PCR?

Anchored PCR is the modification in which only one piece of the sequence is known and thus one primer

The known sequence is attached to the required region of amplification and then further used as a second priming site

Fragment the sample DNA and ligate it to known sequence

Tails are added enzymatically to the region of known sequence

In another method of quantitative PCR, reporter-quencher set up is used. Which of the statement holds true for this methodology?

The quencher is having a fluorescent group

It allows detection of all double stranded molecules

The reporter and quencher are the molecules present on the same probe

The quencher is having a fluorescent group

Fluorescence is observed only when both the groups are present in proximity to each other

Which of the statement hold true for Quantitative PCR?

This approach is useful if the products are non-specific in nature

A fluorescent dye is used which binds on single stranded DNA molecules

SYBR green is an example such type of dye

The quantity of DNA is simply measured by measuring the amount of fluorescence

This approach is useful if the products are non-specific in nature

What is the problem associated with historical DNA samples?

They degrade during repeated cooling and heating cycles

They are less in amount thus amplification is difficult

Because the samples are very old, there can be contamination

They degrade during repeated cooling and heating cycles

As the samples are old, the standard sequences for comparison is not present

How can the specificity of primer annealing be increased?

Adjusting the concentration of sodium ions

Using polymerase with proof reading activity

Which of the following statement is incorrect regarding the cloning of PCR products?

The amplified molecules can be cut at both the ends by appropriate enzymes

In cloning via restriction enzymes, restriction sites are induced before amplification is carried out

The restriction sites are induced in the primers before annealing

The intermediate molecules are having restriction sites at both ends

The amplified molecules can be cut at both the ends by appropriate enzymes

Isothermal amplification is carried out at times. Which of the statement is true?

The repeated heating and cooling required by PCR is not the reason for limiting how quickly the reaction is carried out

It is carried out typically at 65 degrees

It requires expensive PCR machines to be carried out

PCR products can be analysed in many ways. Which of the following is not possible?

Determining whether a particular oliginucleotide probe hybridizes to a PCR product

Direct sequencing can’t be carried out

Topoisomerse I is also used for cloning of PCR product at times. Which of the statement holds true for such type of cloning?

The restriction site is induced into the vector and the topisomerase enzyme is induced into the PCR primers

The topoismerase I is used for cutting both the strands

The induction of topoisomerase enzyme is done into the vector in the case it is very small in size

The restriction site is induced into the PCR primers and the topoisomerase enzyme is induced into the vector

Sickle cell anaemia is a genetic disorder. Which of the following doesn’t holds true for it?

The conventional approach took weeks for the whole analyses to be carried out

The mutation is in alpha globulin gene

The conventional approach took weeks for the whole analyses to be carried out

Which of the statements don’t hold true for the forensics and the amplification carried out?

In cases of bone fragments which contain less than 300 nucleotides conventional methods can’t be applied as they involve southern blotting, restriction digestion etc

In the case of forensics, conventional methods such as southern blotting are used very effectively

In cases of bone fragments which contain less than 300 nucleotides conventional methods can’t be applied as they involve southern blotting, restriction digestion etc

The poor condition of DNA also makes the PCR amplification difficult

Microsatellites composed of simply varying repeats of CA sequences are used

What are the possibilities which can occur until the temperature has reached for primer annealing?

At low temperature, there is specific annealing of primer taking place

Extension doesn’t starts until the appropriate temperature is reached

Extension may start even when the temperature is low

At low temperature, there is specific annealing of primer taking place

There are more specific products which are generated

Which of the statement is incorrect for jumping PCR?

It is used in the case when the DNA fragment is degraded

In this type of PCR, the molecules are not long enough to span between the two primer sites

At the end of first round of synthesis, the extension of the molecule from the primer site to the end of the fragmented molecule takes place

It doesn’t leads to the formation of chimeric product

Errors can be introduced because of many reasons such as polymerase error or because of heterogeneity. Which of the statement holds true?

The error caused by sequence heterogeneity is mainly because of first position in the codon

The error caused because of polymerase is biased for the first position in the codon

The error caused because of polymerase is evenly distributed on all the positions in the codon

The error caused by sequence heterogeneity is mainly because of first position in the codon

The error caused by sequence heterogeneity is evenly distributed on all the codon positions

Emulsion or droplet PCR is another modification of PCR. Which of the statement holds true?

It refers to the PCR carried out at large scale

It is possible to incorporate the reagents in a lipid drop

It refers to the PCR carried out at large scale

The temperature variation is not possible easily

If there is a single template molecule at the start then amplification results in the mixture and it because of the extent of extension carried out

An alternative to adding polymerase at later stage is __________

Introduce the polymerase or Magnesium in clay beads

Make the polymerase inactive by binding it to an antibody

Introduce the polymerase or Magnesium in clay beads

Make the polymerase inactive by attaching groups which cause stearic inhindrance

Introduction of polymerase or Magnesium in plastic wires

During amplification, there are chances of having a product of a mixture of different sequences. There are various ways to detect it. Which of the statement is true in regard to it?

If cloning is done before sequencing, then it is detected via using only a single clone for sequencing

Direct sequencing can’t be used in the case if the template DNA is heterozygous at the locus

Direct sequencing can be used if the template DNA is heterozygous at the locus

If cloning is done before sequencing, then it is detected via using only a single clone for sequencing

In the case several recombinants are used, it can’t go undetected

PCR amplification can be used for which type of samples?

Recent samples are preferred but can be applied to old samples also

Equally to both recent and old samples

Recent samples are preferred but can be applied to old samples also

Which of the following is favoured for primer design?

Matching should be of whole primer to the template

The melting temperature should be different for both the primers

Primers should be long in length

Primers should not be complementary to each other

Matching should be of whole primer to the template

Which one of the following is not done if amplification of the non flanking region is carried out?

Firstly, restriction enzyme digestion is done of those sites whose sequence is not known

Then the self-ligation of molecules is allowed

Now the molecules are cleaved where the known sequence is

Again, the molecules are linearized and the known sequence is in the middle

What is the correct statement with respect to ddNTPs?

They are used for initiating DNA sequencing

They are dideoxynucleotide triphosphates

They are used in the termination of DNA sequencing

They are used for initiating DNA sequencing

They are used in the case if the starting amounts are large

Which of the following conditions don’t contribute to wrong annealing to primer?

The original sequence of the primers

Both the conditions of annealing and the original sequence don’t play any role

Hot-start PCR is a modification of PCR. Which of the following is not corresponding to it?

The basis is that extension is not started until the first cycle reaches its maximum temperature

The polymerase is added after the first cycle has reached its maximum temperature or melting temperature

It is satisfactory for small number of samples

It leads to generation of non specific products

90 + Mcqs in Polymerase Chain Reaction in Genetic Engineering Page 1 McqOptions

1.	The cloning step in PCR/sequencing analysis of microbial communities is necessary for
A.	the amplification process
B.	preventing contamination by outside DNA
C.	separating the different rRNA gene sequences in the mixture
D.	none of these
Answer» D. none of these

2.	DNA fragments in a restriction digest can be separated by electrophoresis in
A.	poly acrylamide
B.	agarose gel
C.	both (a) and (b)
D.	none of these
Answer» D. none of these

3.	Northern blotting is
A.	widely different than southern blotting
B.	another name for southern blotting
C.	analogous to southern blotting
D.	none of the above
Answer» D. none of the above

4.	What technique can be used to determine the murderer who left blood with the victim?
A.	DNA sequencing
B.	PCR amplification
C.	Western blot
D.	RFLP mapping
Answer» C. Western blot

5.	The process of introducing DNA into cells is called ____________________
A.	blotting
B.	conjugation
C.	transfection
D.	conduction
Answer» D. conduction

6.	Viral-mediated gene transfer is called _______________
A.	conjugation
B.	transduction
C.	transformation
D.	transversion
Answer» C. transformation

7.	Bacterial artificial chromosomes are the __________________ of bacterial cells.
A.	Polymerase enzyme
B.	Proteases
C.	F-factors
D.	Exonucleases
Answer» D. Exonucleases

8.	Which of the following can be used to clone DNA sequence of size larger than 25 kb?
A.	Yeast artificial chromosome
B.	SV40
C.	Plasmid
D.	Bacteriophage
Answer» B. SV40

9.	The endonuclease HaeIII recognizes ______________________ sequence.
A.	mono-nucleotide
B.	bi-nucleotide
C.	tri-nucleotide
D.	tetra-nucleotide
Answer» D. tetra-nucleotide

10.	cDNA libraries are produced from ______________________
A.	ribonucleic acids
B.	messenger RNAs
C.	transfer RNAs
D.	ribosomal RNAs
Answer» C. transfer RNAs

11.	DNA libraries are collection of ______________________
A.	ribonucleic acid
B.	cloned DNA fragments
C.	bacteriophages
D.	viral particles
Answer» C. bacteriophages

12.	When was the nucleotide sequence of a viral genome first elucidated?
A.	1977
B.	1988
C.	1999
D.	2002
Answer» B. 1988

13.	Molecular beacons are short ____________________
A.	polysaccarides
B.	monosaccharides
C.	oligonucleotides
D.	phospholipids
Answer» D. phospholipids

14.	PCR can generate large amounts of DNA.
A.	True
B.	False
Answer» B. False

16.	The temperature cycles in a polymerase chain reaction are in the order __________________
A.	95°, 60°, 72°
B.	60°, 72°, 95°
C.	72°, 60°, 95°
D.	95°, 72°, 60°
Answer» B. 60°, 72°, 95°

15.	Which enzyme is active at 72° in the polymerase chain reaction?
A.	isomerase
B.	exonuclease
C.	polymerase
D.	endonuclease
Answer» D. endonuclease

17.	Taq polymerase is a ________________________ polymerase.
A.	heat-stable
B.	buffering
C.	denaturant
D.	large
Answer» B. buffering

18.	Polymerase chain reaction (PCR) was invented by ______________________
A.	Kary Mullis
B.	James Watson
C.	John Hopkins
D.	Hargobind Khorana
Answer» B. James Watson

19.	Bacteriophage Lambda is a major cloning vector.
A.	True
B.	False
Answer» B. False

24.	How can the specificity of primer annealing be increased?
A.	Use of short primers
B.	Raising temperature
C.	Adjusting the concentration of sodium ions
D.	Using polymerase with proof reading activity
Answer» C. Adjusting the concentration of sodium ions

26.	There are basically two types of contamination, laboratory and external. If a PCR product is found to be contaminated by bacteria. It comes under laboratory contamination.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

28.	PCR products can be analysed in many ways. Which of the following is not possible?
A.	Use of restriction enzymes
B.	Determining whether a particular oliginucleotide probe hybridizes to a PCR product
C.	Electrophoresis
D.	Direct sequencing can’t be carried out
Answer» E.

29.	By using two oligonucleotides, we can measure the amount of quantity of DNA by measuring the amount of fluorescence. The first probe absorbs light and the second emits it at a particular wavelength.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

31.	Mutation is never deliberately induced in PCR products.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

32.	The primer annealing temperature is often very low from the maximum temperature. This low temperature leads to some mismatches.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Explore topic-wise MCQs in Genetic Engineering.

The cloning step in PCR/sequencing analysis of microbial communities is necessary for

DNA fragments in a restriction digest can be separated by electrophoresis in

Northern blotting is

What technique can be used to determine the murderer who left blood with the victim?

The process of introducing DNA into cells is called ____________________

Viral-mediated gene transfer is called _______________

Bacterial artificial chromosomes are the __________________ of bacterial cells.

Which of the following can be used to clone DNA sequence of size larger than 25 kb?

The endonuclease HaeIII recognizes ______________________ sequence.

cDNA libraries are produced from ______________________

DNA libraries are collection of ______________________

When was the nucleotide sequence of a viral genome first elucidated?

Molecular beacons are short ____________________

PCR can generate large amounts of DNA.

Which enzyme is active at 72° in the polymerase chain reaction?

The temperature cycles in a polymerase chain reaction are in the order __________________

Taq polymerase is a ________________________ polymerase.

Polymerase chain reaction (PCR) was invented by ______________________

Bacteriophage Lambda is a major cloning vector.