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Recombinant DNA Technology Quiz

Total questions: 153

Worksheet time: 4hrs 50mins

Name
Class
Date
1.

What is the first step in recombinant DNA technology?

a)

Introduction of rDNA into host cells

b)

Isolation of the gene of interest

c)

Ligation of DNA fragments

d)

Transformation of the host cells

2.

Which enzyme is primarily used to cut DNA at specific sites in recombinant DNA technology?

a)

DNA ligase

b)

DNA polymerase

c)

Restriction endonuclease

d)

RNA polymerase

3.

What characteristic must a plasmid have to function as a cloning vector?

a)

It must replicate independently within the host

b)

It should not have a selectable marker

c)

It should be larger than 100 kilobases

d)

It must contain at least five different antibiotic resistance genes

4.

In which year were the first recombinant DNA molecules generated?

a)

1953

b)

1973

c)

1985

d)

2001

5.

What is the function of DNA ligase in recombinant DNA technology?

a)

To cut DNA at specific sequences

b)

To join DNA fragments together

c)

To separate DNA strands

d)

To amplify DNA

6.

The process of introducing recombinant DNA into a host cell is known as:

a)

Transformation

b)

Cloning

c)

Transfection

d)

Electroporation

7.

Which type of restriction enzyme is commonly used in recombinant DNA technology?

a)

Type I

b)

Type II

c)

Type III

d)

Type IV

8.

What is a 'sticky end' in the context of recombinant DNA technology?

a)

A blunt end of a DNA fragment

b)

An overhanging single-stranded DNA region after cutting with certain enzymes

c)

A circular plasmid DNA without any cuts

d)

A double-stranded DNA region

9.

The selectable marker in a plasmid vector is used to:

a)

Identify vectors that have not been taken up by host cells

b)

Cut the DNA at specific sites

c)

Allow plasmid replication in the host

d)

Identify cells that have successfully taken up the vector

10.

Which method uses an electric field to introduce DNA into host cells?

a)

Microinjection

b)

Electroporation

c)

Transfection

d)

Transformation

11.

Which scientist is credited with the invention of the Polymerase Chain Reaction (PCR)?

a)

Paul Berg

b)

Stanley Cohen

c)

Kerry Mullis

d)

Herbert Boyer

12.

Which of the following is NOT a characteristic feature of a good cloning vector?

a)

Presence of an origin of replication

b)

Large size to accommodate more DNA

c)

Presence of a selectable marker

d)

Multiple cloning sites

13.

The enzyme responsible for creating phosphodiester bonds during ligation is:

a)

Restriction enzyme

b)

DNA ligase

c)

Helicase

d)

DNA polymerase

14.

Which type of host cell is most commonly used in recombinant DNA experiments?

a)

Yeast cells

b)

E. coli

c)

Plant cells

d)

Animal cells

15.

Which enzyme is used to prevent self-ligation of the vector?

a)

DNA ligase

b)

Alkaline phosphatase

c)

Restriction enzyme

d)

Taq polymerase

16.

A DNA fragment inserted into a plasmid is known as the:

a)

Insert

b)

Vector

c)

Ligase

d)

Primer

17.

Which method is used to transfer DNA into plant cells by bombarding them with microscopic particles?

a)

Microinjection

b)

Electroporation

c)

Biolistics

d)

Transfection

18.

DNA molecules with blunt ends can be joined together by:

a)

DNA ligase

b)

Restriction enzyme

c)

Alkaline phosphatase

d)

Reverse transcriptase

19.

What is a 'cosmid' in the context of recombinant DNA technology?

a)

A plasmid with cos sites from phage lambda

b)

A bacteriophage used to infect cells

c)

A yeast artificial chromosome

d)

A type of DNA probe

20.

The term 'hybridization' in molecular biology refers to:

a)

Cutting DNA using restriction enzymes

b)

Joining two DNA fragments together

c)

Binding of complementary DNA strands

d)

Amplifying DNA using PCR

21.

Which enzyme is essential for converting mRNA into complementary DNA (cDNA)?

a)

DNA polymerase

b)

Reverse transcriptase

c)

RNA polymerase

d)

Taq polymerase

22.

Which plasmid is commonly used in genetic engineering of plants?

a)

pBR322

b)

pUC19

c)

Ti plasmid

d)

F plasmid

23.

What is the purpose of using agarose gel electrophoresis in recombinant DNA experiments?

a)

To amplify DNA

b)

To cut DNA at specific sites

c)

To separate DNA fragments based on size

d)

To join DNA fragments together

24.

The phenomenon where a gene becomes nonfunctional due to the insertion of foreign DNA is called:

a)

Transformation

b)

Insertional inactivation

c)

Transfection

d)

Electroporation

25.

Which type of vector is used to clone large DNA fragments up to 1 Mb in size?

a)

Plasmid

b)

Cosmid

c)

YAC (Yeast Artificial Chromosome)

d)

BAC (Bacterial Artificial Chromosome)

26.

Which enzyme is used in the Polymerase Chain Reaction (PCR) due to its heat stability?

a)

DNA ligase

b)

Taq polymerase

c)

RNA polymerase

d)

Reverse transcriptase

27.

The term 'blunt ends' in DNA refers to:

a)

DNA fragments with overhanging ends

b)

DNA fragments with no overhangs

c)

Single-stranded DNA regions

d)

DNA fragments circularized

28.

Which type of restriction enzyme recognizes palindromic sequences and cuts within the recognition site?

a)

Type I

b)

Type II

c)

Type III

d)

Type IV

29.

Which feature is commonly present in an expression vector?

a)

Only the origin of replication

b)

Gene coding for antibiotic resistance

c)

Promoter and terminator sequences for transcription

d)

Only selectable markers

30.

A DNA library is a collection of:

a)

Different types of plasmids

b)

All DNA fragments from an organism's genome

c)

Enzymes used in molecular biology

d)

RNA sequences from various organisms

31.

Which of the following is an example of a cloning vector?

a)

Yeast cells

b)

pBR322

c)

Agarose gel

d)

DNA polymerase

32.

The selectable marker gene is used to:

a)

Separate DNA fragments

b)

Identify cells containing the vector

c)

Join DNA fragments together

d)

Cut DNA at specific sites

33.

Which hybridization technique is used to detect RNA sequences?

a)

Southern blotting

b)

Northern blotting

c)

Western blotting

d)

Eastern blotting

34.

Which DNA sequencing method uses dideoxynucleotides for chain termination?

a)

Maxam-Gilbert method

b)

PCR-based sequencing

c)

Sanger sequencing

d)

RNA sequencing

35.

In recombinant DNA technology, the term 'vector' refers to:

a)

The host cell

b)

An enzyme used in DNA cutting

c)

A vehicle to transfer genetic material into cells

d)

A technique used for DNA amplification

36.

The process of using bacterial cells to take up plasmid DNA is called:

a)

Electroporation

b)

Transfection

c)

Transformation

d)

Biolistics

37.

Which component is NOT required in a typical PCR reaction?

a)

Primers

b)

DNA ligase

c)

Template DNA

d)

Deoxynucleotide triphosphates

38.

The recognition sequence for the restriction enzyme EcoRI is:

a)

5'–GCGC–3'

b)

5'–GAATTC–3'

c)

5'–ATGC–3'

d)

5'–GGCC–3'

39.

In blue-white selection, what color will colonies with the recombinant plasmid appear?

a)

Blue

b)

White

c)

Green

d)

Red

40.

A probe used in hybridization techniques is typically:

a)

A restriction enzyme

b)

A single-stranded DNA or RNA sequence

c)

An antibody

d)

A double-stranded DNA fragment

41.

Are restriction enzymes?

a)

A restriction enzyme

b)

A single-stranded DNA or RNA sequence

c)

An antibody

d)

A double-stranded DNA fragment

42.

A genomic library differs from a cDNA library in that it:

a)

Contains only expressed genes

b)

Represents the entire genome, including non-coding regions

c)

Is smaller in size

d)

Is used only for eukaryotic organisms

43.

Which type of host cell is often used to express eukaryotic proteins due to the need for post-translational modifications?

a)

E. coli

b)

Yeast cells

c)

Bacteriophages

d)

Plasmids

44.

What is the role of reverse transcriptase in recombinant DNA technology?

a)

To replicate DNA

b)

To transcribe RNA into DNA

c)

To cut DNA at specific sites

d)

To repair DNA strands

45.

The term 'biolistics' refers to:

a)

Using electric pulses to introduce DNA

b)

Bombarding cells with DNA-coated particles

c)

Injecting DNA directly into cells

d)

Using chemical treatments to facilitate DNA uptake

46.

DNA ligase is primarily used to:

a)

Cut DNA molecules

b)

Amplify DNA molecules

c)

Join DNA fragments together

d)

Denature DNA strands

47.

Which technique is commonly used for DNA fingerprinting?

a)

PCR

b)

Southern hybridization

c)

Blue-white selection

d)

Electrophoresis

48.

The enzyme used to extend primers during PCR is:

a)

Restriction endonuclease

b)

Taq polymerase

c)

Alkaline phosphatase

d)

DNA ligase

49.

A 'cos site' is a feature of:

a)

Plasmids

b)

Bacteriophage lambda

c)

Yeast artificial chromosomes

d)

Bacterial artificial chromosomes

50.

Which method can be used to prevent plasmids from self-ligating during cloning?

a)

Treating with Taq polymerase

b)

Using alkaline phosphatase

c)

Adding more ligase

d)

Increasing the temperature

51.

The size of DNA fragments cloned in a BAC vector can be up to:

a)

8 kb

b)

23 kb

c)

500 kb

d)

1 Mb

52.

Which of the following is a natural source of plasmids?

a)

Bacteriophages

b)

Bacteria

c)

Yeast

d)

Viruses

53.

Which of these methods is commonly used to verify the presence of a recombinant DNA molecule in a host cell?

a)

Blue-white screening

b)

Southern blotting

c)

PCR

d)

Northern blotting

54.

DNA sequencing by the Sanger method involves the use of:

a)

RNA primers

b)

Dideoxynucleotides

c)

Restriction enzymes

d)

Taq polymerase

55.

The process of increasing the number of copies of a specific DNA segment is called:

a)

Transformation

b)

Cloning

c)

Amplification

d)

Hybridization

56.

Which term refers to a vector that can replicate in both prokaryotic and eukaryotic cells?

a)

Shuttle vector

b)

Expression vector

c)

Cloning vector

d)

Viral vector

57.

In the context of DNA cloning, the term 'ligation' refers to:

a)

Cutting DNA at specific sites

b)

Joining two DNA fragments together

c)

Amplifying a specific DNA sequence

d)

Inserting DNA into a host cell

58.

The Ti plasmid, used in plant genetic engineering, is derived from:

a)

Bacillus thuringiensis

b)

Escherichia coli

c)

Agrobacterium tumefaciens

d)

Rhizobium radiobacter

59.

Which type of DNA ends are produced by restriction enzymes like EcoRI?

a)

Blunt ends

b)

Sticky ends

c)

Double-stranded ends

d)

Circular ends

60.

The enzyme responsible for synthesizing a complementary strand of DNA from an RNA template is called:

a)

Taq polymerase

b)

Reverse transcriptase

c)

DNA ligase

d)

RNA polymerase

61.

A multiple cloning site (MCS) in a plasmid vector:

a)

Is used for replication

b)

Contains several restriction enzyme sites for cloning

c)

Provides antibiotic resistance

d)

Is responsible for plasmid stability

62.

Which enzyme adds phosphate groups to DNA molecules?

a)

DNA ligase

b)

DNA polymerase

c)

Alkaline phosphatase

d)

Kinase

63.

PCR is an effective technique for:

a)

Amplifying large amounts of a specific DNA segment

b)

Sequencing the entire genome

c)

Transcribing RNA into DNA

d)

Cutting DNA at specific sites

64.

In Southern blotting, the DNA is transferred from the gel to a:

a)

Nylon or nitrocellulose membrane

b)

Glass slide

c)

Agar plate

d)

Polyacrylamide sheet

65.

The function of a selectable marker gene in a cloning vector is to:

a)

Make the vector circular

b)

Allow identification of cells that have taken up the vector

c)

Amplify the DNA fragment

d)

Cut the DNA at specific sites

66.

Which component is not required for the Sanger sequencing method?

a)

DNA polymerase

b)

Dideoxynucleotides

c)

Primers

d)

Reverse transcriptase

67.

Which enzyme joins the DNA fragments during the ligation process?

a)

Restriction enzyme

b)

DNA ligase

c)

DNA polymerase

d)

Helicase

68.

The use of yeast artificial chromosomes (YACs) is ideal for cloning:

a)

Small DNA fragments

b)

DNA fragments less than 5 kb

c)

Large DNA fragments, over 1 Mb

d)

Plasmid-sized DNA fragments

69.

Site-directed mutagenesis is used to:

a)

Create random mutations

b)

Introduce specific changes into a DNA sequence

c)

Cut DNA at specific sites

d)

Join DNA fragments together

70.

What is the purpose of using agarose in gel electrophoresis?

a)

To amplify DNA

b)

To separate DNA fragments by size

c)

To ligate DNA fragments

d)

To hybridize with probes

71.

In PCR, the step that separates the DNA strands is known as:

a)

Annealing

b)

Extension

c)

Denaturation

d)

Hybridization

72.

Which type of vector is specifically designed for expressing foreign proteins in host cells?

a)

Cloning vector

b)

Expression vector

c)

Shuttle vector

d)

Phage vector

73.

The sticky ends produced by the same restriction enzyme can be:

a)

Ligated together because they are complementary

b)

Used to separate DNA fragments

c)

Amplified by PCR

d)

Sequenced using the Sanger method

74.

A BAC (Bacterial Artificial Chromosome) is used to clone DNA fragments of up to:

a)

10 kb

b)

100 kb

c)

500 kb

d)

1 Mb

75.

Which of the following is an example of a selectable marker gene?

a)

ori

b)

lacZ

c)

Ampicillin resistance gene

d)

Taq polymerase

76.

Which organism is commonly used to create transgenic plants?

a)

Bacillus thuringiensis

b)

Escherichia coli

c)

Agrobacterium tumefaciens

d)

Rhizobium radiobacter

77.

The enzyme used to extend the primers in PCR is:

a)

DNA ligase

b)

Taq polymerase

c)

Restriction enzyme

d)

Reverse transcriptase

78.

A DNA probe can be labeled with:

a)

Antibiotics

b)

Fluorescent dyes or radioactive isotopes

c)

Restriction enzymes

d)

Electrophoresis dyes

79.

Which of the following statements about plasmids is false?

a)

They are usually circular DNA molecules

b)

They can replicate independently of the chromosomal DNA

c)

They are always found in eukaryotic cells

d)

They often carry antibiotic resistance genes

80.

PCR requires primers that:

a)

Are single-stranded DNA oligonucleotides

b)

Are double-stranded DNA molecules

c)

Are made up of RNA

d)

Contain fluorescent labels

81.

A genomic DNA library contains:

a)

Only expressed genes

b)

The entire genome, including non-coding regions

c)

Only coding regions

d)

A mixture of DNA fragments

82.

A genomic DNA library contains:

a)

Only expressed genes

b)

Entire genome, including non-coding sequences

c)

Only protein-coding genes

d)

Only mitochondrial DNA

83.

The introduction of recombinant DNA into a host cell is called:

a)

Transcription

b)

Transformation

c)

Translation

d)

Transduction

84.

In the dideoxy method of DNA sequencing, the addition of a dideoxynucleotide causes:

a)

DNA synthesis to continue normally

b)

Chain termination

c)

Amplification of DNA

d)

Removal of introns

85.

Which of the following is a naturally occurring plasmid used in genetic engineering of plants?

a)

pBR322

b)

pUC19

c)

Ti plasmid

d)

R plasmid

86.

The process used to identify specific DNA fragments from a DNA library is:

a)

Electroporation

b)

DNA sequencing

c)

Hybridization with a labeled probe

d)

Polymerase chain reaction

87.

Which enzyme is used to create cDNA from mRNA?

a)

DNA ligase

b)

Taq polymerase

c)

Reverse transcriptase

d)

RNA polymerase

88.

What is the role of alkaline phosphatase in recombinant DNA technology?

a)

To add phosphate groups to DNA ends

b)

To remove phosphate groups from DNA ends

c)

To cut DNA at specific sequences

d)

To ligate DNA fragments

89.

Which technique is used for amplifying minute quantities of DNA?

a)

Southern blotting

b)

Polymerase chain reaction (PCR)

c)

Gel electrophoresis

d)

Site-directed mutagenesis

90.

The enzyme used to 'seal' nicks in the DNA backbone during the ligation process is:

a)

DNA polymerase

b)

DNA ligase

c)

Restriction endonuclease

d)

Topoisomerase

91.

The sticky ends produced by restriction enzymes like HindIII are useful because they:

a)

Help in the easy separation of DNA fragments

b)

Facilitate the joining of DNA fragments with complementary ends

c)

Prevent DNA fragments from self-ligating

d)

Make the DNA more stable

92.

A cDNA library is constructed using:

a)

Genomic DNA

b)

mRNA

c)

rRNA

d)

Plasmid DNA

93.

The plasmid pBR322 contains genes for resistance to:

a)

Ampicillin and tetracycline

b)

Kanamycin and neomycin

c)

Chloramphenicol and erythromycin

d)

Streptomycin and penicillin

94.

What is the purpose of including antibiotic resistance genes in plasmid vectors?

a)

To aid in the replication of the plasmid

b)

To help identify transformed cells

c)

To facilitate the cutting of DNA at specific sites

d)

To increase the size of the plasmid

95.

Which technique is used to separate DNA fragments based on size?

a)

Polymerase chain reaction

b)

DNA ligation

c)

Gel electrophoresis

d)

DNA sequencing

96.

Which type of DNA library contains all the DNA sequences from an organism's genome?

a)

cDNA library

b)

Genomic library

c)

Plasmid library

d)

Mitochondrial DNA library

97.

The recognition site for a restriction enzyme is usually:

a)

A random DNA sequence

b)

A palindromic DNA sequence

c)

An RNA sequence

d)

A protein sequence

98.

The recombinant DNA technique used to introduce foreign DNA into mammalian cells by using lipid-based carriers is called:

a)

Transformation

b)

Electroporation

c)

Lipofection

d)

Transduction

99.

The enzyme used to join two DNA fragments together is:

a)

Taq polymerase

b)

DNA ligase

c)

RNA polymerase

d)

Restriction enzyme

100.

Which method is used to identify recombinant colonies using a substrate that changes color?

a)

Replicaplating

b)

Southern blotting

c)

Blue-white screening

d)

PCR-based screening

101.

The 3' end of a DNA strand has:

a)

A phosphate group

b)

A hydroxyl group

c)

A nitrogenous base

d)

A methyl group

102.

PCR amplification follows which sequence of steps?

a)

Annealing, denaturation, extension

b)

Extension, denaturation, annealing

c)

Denaturation, annealing, extension

d)

Denaturation, extension, annealing

103.

Which of the following is a method used for DNA fingerprinting?

a)

Western blotting

b)

Northern blotting

c)

Southern blotting

d)

Eastern blotting

104.

Which enzyme is heat-stable and used during the extension step of PCR?

a)

DNA ligase

b)

Taq polymerase

c)

Reverse transcriptase

d)

RNA polymerase

105.

An example of a gene used as a reporter gene in molecular biology experiments is:

a)

Ampicillin resistance gene

b)

Green Fluorescent Protein (GFP)

c)

lacZ

d)

pBR322

106.

The purpose of using a probe in a Southern blot is to:

a)

Cut DNA at specific sites

b)

Label DNA with fluorescent markers

c)

Identify specific DNA fragments by hybridization

d)

Separate DNA fragments by size

107.

The principle behind hybridization techniques is based on:

a)

The replication of DNA strands

b)

The binding of complementary nucleotide sequences

c)

The joining of DNA fragments with ligase

d)

The amplification of specific DNA sequences

108.

A DNA fragment containing only coding regions of a gene, free from introns, is obtained from:

a)

Genomic DNA library

b)

cDNA library

c)

Plasmid DNA

d)

Mitochondrial DNA

109.

DNA fingerprinting can be used to:

a)

Identify genetic disorders

b)

Sequence the entire genome

c)

Determine evolutionary relationships

d)

Identify individuals based on their unique DNA patterns

110.

In PCR, primers anneal to the template DNA during which step?

a)

Denaturation

b)

Extension

c)

Annealing

d)

Sequencing

111.

The function of the ori site in a plasmid vector is:

a)

To cut DNA at specific sites

b)

To facilitate DNA replication

c)

To confer antibiotic resistance

d)

To insert the foreign DNA

112.

What is the main purpose of gel electrophoresis in molecular biology?

a)

To replicate DNA

b)

To measure the size of DNA fragments

c)

To amplify specific DNA sequences

d)

To hybridize DNA fragments

113.

Which method is used to introduce foreign DNA directly into plant cells using microscopic particles?

a)

Microinjection

b)

Biolistics

c)

Electroporation

d)

Transduction

114.

Which type of cloning vector can accommodate the largest DNA insert?

a)

Plasmid

b)

Cosmid

c)

Bacterial Artificial Chromosome (BAC)

d)

Yeast Artificial Chromosome (YAC)

115.

The process of using electric pulses to introduce DNA into host cells is called:

a)

Electroporation

b)

Microinjection

c)

Lipofection

d)

Transformation

116.

In a DNA sequencing reaction, the purpose of adding dideoxynucleotides is to:

a)

Start the DNA synthesis process

b)

Terminate DNA synthesis at specific points

c)

Cut DNA at certain locations

d)

Stabilize the DNA strands

117.

A selectable marker is used in recombinant DNA technology to:

a)

Identify vectors that have been successfully ligated

b)

Confirm the size of the DNA insert

c)

Identify host cells that have taken up the vector

d)

Amplify the cloned DNA fragment

118.

Which of the following enzymes is used to cut DNA at specific sites?

a)

DNA ligase

b)

Restriction endonuclease

c)

DNA polymerase

d)

Reverse transcriptase

119.

Which enzyme is used to cut DNA at specific sites?

a)

DNAligase

b)

Restriction endonuclease

c)

DNA polymerase

d)

Reverse transcriptase

120.

DNA fragments in gel electrophoresis migrate towards the:

a)

Positive electrode (anode)

b)

Negative electrode (cathode)

c)

Center of the gel

d)

Upper portion of the gel

121.

The initial step in creating recombinant DNA is to:

a)

Amplify DNA using PCR

b)

Ligate the DNA fragments

c)

Isolate the DNA of interest

d)

Transform the host cells

122.

During PCR, what is the temperature range for the denaturation step?

a)

50–60°C

b)

60–70°C

c)

80–90°C

d)

90–95°C

123.

What is the primary function of a multiple cloning site (MCS) in a plasmid vector?

a)

To replicate the plasmid

b)

To facilitate ligation of DNA inserts

c)

To confer antibiotic resistance

d)

To enable transcription of inserted genes

124.

Which of the following statements about restriction enzymes is true?

a)

They randomly cut DNA molecules.

b)

They cut DNA at specific recognition sequences.

c)

They only function at high temperatures.

d)

They are used to ligate DNA fragments.

125.

DNA ligase is required during recombinant DNA construction to:

a)

Separate DNA strands

b)

Join DNA fragments together

c)

Denature DNA strands

d)

Replicate DNA

126.

What is the significance of sticky ends produced by restriction enzyme digestion?

a)

They prevent DNA fragments from ligating.

b)

They allow complementary base pairing for ligation.

c)

They make DNA fragments less stable.

d)

They are not useful in cloning.

127.

Which term refers to the process of introducing recombinant DNA into eukaryotic cells using a fine needle?

a)

Electroporation

b)

Microinjection

c)

Biolistics

d)

Transformation

128.

What is the main advantage of using cDNA over genomic DNA for cloning eukaryotic genes?

a)

cDNA contains introns

b)

cDNA is derived from mRNA and represents expressed genes only

c)

cDNA is more stable than genomic DNA

d)

cDNA contains regulatory sequences

129.

The term 'insertional inactivation' refers to:

a)

The process of removing introns from a gene

b)

The inactivation of a gene due to the insertion of foreign DNA

c)

The amplification of DNA fragments

d)

The ligation of DNA fragments

130.

PCR requires which of the following components?

a)

DNA ligase

b)

RNA primers

c)

Single-stranded DNA template

d)

Double-stranded DNA primers

131.

What is the function of Taq polymerase in PCR?

a)

To denature DNA

b)

To join DNA fragments together

c)

To synthesize new DNA strands

d)

To cut DNA at specific sites

132.

Which type of DNA ends can be ligated using DNA ligase?

a)

Blunt ends only

b)

Sticky ends only

c)

Both blunt and sticky ends

d)

Neither blunt nor sticky ends

133.

What does the term 'recombinant DNA' refer to?

a)

DNA synthesized artificially from two or more different sources

b)

DNA that is isolated from a natural organism

c)

DNA that cannot be replicated in a host cell

d)

DNA that is only found in viruses

134.

The lacZ gene in plasmid vectors is often used in blue-white screening because:

a)

It produces a red-colored product.

b)

It confers antibiotic resistance.

c)

It encodes the enzyme β-galactosidase, which hydrolyzes X-Gal.

d)

It is required for plasmid replication.

135.

A genomic DNA library represents:

a)

Only coding regions of the genome.

b)

The entire genome, including both coding and non-coding regions.

c)

A selected portion of the genome.

d)

Only expressed genes.

136.

The 'ori' site in a plasmid is important because it:

a)

Allows the plasmid to replicate within the host cell.

b)

Provides resistance to antibiotics.

c)

Is used for blue-white screening.

d)

Prevents the plasmid from self-ligating.

137.

DNA ligase catalyzes the formation of:

a)

Hydrogen bonds between complementary bases.

b)

Phosphodiester bonds between nucleotides.

c)

Peptide bonds between amino acids.

d)

Covalent bonds between sugars and phosphates.

138.

Which of the following is a commonly used reporter gene in molecular biology?

a)

GFP (Green Fluorescent Protein)

b)

ori

c)

EcoRI

d)

Taq polymerase

139.

The DNA fingerprinting technique utilizes:

a)

PCR amplification of repetitive sequences.

b)

Transcription and translation of DNA.

c)

Cloning and expression of recombinant proteins.

d)

Hybridization with RNA probes.

140.

Which enzyme is used to synthesize complementary DNA (cDNA) from an mRNA template?

a)

Taq polymerase

b)

DNA ligase

c)

Reverse transcriptase

d)

RNA polymerase

141.

The purpose of using a DNA probe is to:

a)

Cut DNA at specific locations.

b)

Visualize specific DNA fragments through hybridization.

c)

Amplify the DNA sequence.

d)

Separate DNA fragments by size.

142.

Which molecule is commonly used as a substrate in blue-white screening?

a)

X-Gal

b)

IPTG

c)

Ampicillin

d)

Ethidium bromide

143.

Plasmid vectors often contain a selectable marker gene to:

a)

Ensure the DNA remains single-stranded.

b)

Help identify bacteria that have taken up the plasmid.

c)

Enhance the process of DNA ligation.

d)

Control the expression of the recombinant protein.

144.

The enzyme used in PCR that is resistant to high temperatures is known as:

a)

DNA ligase

b)

Reverse transcriptase

c)

Taq polymerase

d)

RNA polymerase

145.

In recombinant DNA technology, 'vectors' are used to:

a)

Cut DNA molecules at specific sites

b)

Ligate DNA fragments

c)

Carry foreign DNA into a host cell

d)

Sequence DNA fragments

146.

The recognition sequence for EcoRI is:

a)

5'–GATC–3'

b)

5'–GAATTC–3'

c)

5'–GGCC–3'

d)

5'–AATT–3'

147.

A cDNA library is constructed using:

a)

Genomic DNA

b)

Ribosomal RNA

c)

mRNA

d)

Plasmid DNA

148.

The purpose of using antibiotic resistance genes in plasmid vectors is to:

a)

Enable replication of the plasmid

b)

Facilitate the ligation of DNA inserts

c)

Select for cells that have taken up the plasmid

d)

Enhance DNA sequencing

149.

The enzyme used to generate cDNA from an RNA template is:

a)

DNA ligase

b)

Reverse transcriptase

c)

Taq polymerase

d)

RNA polymerase

150.

In gel electrophoresis, DNA fragments migrate towards the:

a)

Positive electrode (anode)

b)

Negative electrode (cathode)

c)

Center of the gel

d)

Top of the gel

151.

The DNA fingerprinting technique often uses which type of repetitive sequences?

a)

Single-copy genes

b)

Microsatellites

c)

mRNA sequences

d)

Introns

152.

DNA fragments with 'blunt ends' are generated by:

a)

Sticky-end restriction enzymes

b)

DNA polymerase

c)

Blunt-end restriction enzymes

d)

RNA polymerase

153.

The first step in creating a recombinant plasmid involves:

a)

Transformation of the host cells

b)

Insertion of DNA into the vector

c)

Cutting the