Gene Cloning and Expression: A Comprehensive Guide for Medical Students

Question 1

Which enzyme is specifically used to cleave DNA at particular nucleotide sequences?

Accepted Answer

Restriction enzyme

Answer

Polymerase

Answer

Ligase

Answer

Helicase

Question 2

What is the term for the process of joining two distinct DNA segments together?

Accepted Answer

Ligation

Answer

Restriction

Answer

Transformation

Answer

Annealing

Question 3

What is the primary purpose of a selectable marker in gene cloning?

Accepted Answer

To enable the identification of successfully transformed cells

Answer

To regulate the expression of the cloned gene

Answer

To provide a specific site for restriction enzyme digestion

Answer

To enhance the stability of the cloned DNA fragment

Question 4

What is the main advantage of utilizing PCR in gene cloning?

Accepted Answer

It can amplify a specific region of DNA with high specificity

Answer

It eliminates the need for restriction enzymes

Answer

It is a high-throughput method, allowing for rapid cloning

Answer

It can be used to clone large fragments of DNA efficiently

Question 5

Which enzyme catalyzes the ligation reaction used to connect DNA fragments during gene cloning?

Accepted Answer

Ligase

Answer

Restriction endonuclease

Answer

DNA polymerase

Answer

Helicase

Question 6

Which technique is commonly used to introduce foreign DNA into bacterial cells?

Accepted Answer

Transformation

Answer

Transfection

Answer

Electroporation

Answer

Microinjection

Question 7

The process of separating DNA fragments based on their size and charge is known as:

Accepted Answer

Gel electrophoresis

Answer

PCR

Answer

Restriction digestion

Answer

Ligation

Question 8

Which technique allows for the amplification of specific DNA sequences, producing multiple copies?

Accepted Answer

PCR

Answer

Southern blotting

Answer

Northern blotting

Answer

Western blotting

Question 9

The lac operon serves as a well-studied example of:

Accepted Answer

Gene regulation mechanisms controlling gene expression

Answer

DNA replication processes

Answer

Transcription factors involved in gene transcription

Answer

Translation mechanisms responsible for protein synthesis

Question 10

Which of the following is not a crucial step in the gene cloning process?

Accepted Answer

Southern blotting

Answer

Restriction enzyme digestion

Answer

Ligation

Answer

Transformation

Question 11

Which restriction enzyme specifically recognizes and cuts the palindromic DNA sequence 5'-GAATTC-3'?

Accepted Answer

EcoRI

Answer

HindIII

Answer

BamHI

Answer

XbaI

Question 12

In the context of gene cloning, what is the primary function of ligase?

Accepted Answer

To covalently join DNA fragments together

Answer

To cleave DNA at specific recognition sites

Answer

To amplify DNA fragments

Answer

To separate DNA fragments based on size

Question 13

Which of the following is NOT a commonly used selectable marker in gene cloning?

Accepted Answer

Green fluorescent protein (GFP) expression

Answer

Kanamycin resistance

Answer

Ampicillin resistance

Answer

Tetracycline resistance

Question 14

What is the process of introducing recombinant DNA into a recipient organism commonly referred to as?

Accepted Answer

Transformation

Answer

Transfection

Answer

Transduction

Answer

Electroporation

Question 15

What is the primary purpose of Southern blotting in gene cloning?

Accepted Answer

To detect the presence of a specific DNA sequence in a sample

Answer

To amplify a target DNA sequence

Answer

To determine the size of a DNA fragment

Answer

To clone a gene of interest

Question 16

Among prokaryotic expression systems, which is widely used?

Accepted Answer

E. coli

Answer

Yeast

Answer

Mammalian cells

Answer

Insect cells

Question 17

What is the fundamental difference between constitutive and inducible promoters?

Accepted Answer

Constitutive promoters are continuously active, while inducible promoters require a specific signal to become active.

Answer

Inducible promoters are continuously active, while constitutive promoters require a specific signal to become active.

Answer

Both constitutive and inducible promoters require a specific signal to become active.

Answer

Neither constitutive nor inducible promoters require a specific signal to become active.

Question 18

Which technique is commonly employed to measure the expression level of a particular gene?

Accepted Answer

Northern blotting

Answer

Western blotting

Answer

PCR

Answer

DNA sequencing

Question 19

Describe the fundamental principle behind PCR-based gene cloning techniques.

Accepted Answer

PCR amplifies specific DNA sequences for cloning into a vector.

Answer

Restriction enzymes cut DNA at specific sites.

Answer

Gel electrophoresis separates DNA fragments by size.

Answer

DNA ligase joins DNA fragments together.

Question 20

What is the main role of molecular chaperones in the expression of recombinant proteins?

Accepted Answer

Binding to exposed hydrophobic regions of proteins, preventing aggregation and promoting proper folding

Answer

Assisting in the initiation of protein translation

Answer

Degrading misfolded or damaged proteins

Answer

Transporting proteins to their final cellular destination

Question 21

Which enzyme precisely cleaves DNA at specific recognition sequences, creating cohesive ends?

Accepted Answer

Restriction enzyme

Answer

Polymerase

Answer

Ligase

Answer

Helicase

Question 22

What is the process of covalently bonding DNA fragments together called?

Accepted Answer

Ligation

Answer

Transformation

Answer

Annealing

Answer

Denaturation

Question 23

Which type of vector is most frequently employed for cloning foreign genes in bacteria?

Accepted Answer

Plasmid

Answer

Cosmid

Answer

YAC

Answer

BAC

Question 24

What is the primary function of the selectable marker gene in a cloning vector?

Accepted Answer

To distinguish transformed cells from non-transformed cells

Answer

To amplify the cloned gene

Answer

To regulate gene expression

Answer

To enhance cell survival

Question 25

Which of the following is not an essential component of a gene expression system?

Accepted Answer

Enhancer

Answer

Promoter

Answer

Ribosome binding site

Answer

Transcription termination signal

Question 26

What is the primary purpose of a reporter gene in gene expression studies?

Accepted Answer

To quantify gene expression levels

Answer

To confirm successful gene cloning

Answer

To regulate protein expression

Answer

To amplify the cloned gene

Question 27

Which technique is commonly used to analyze the expression of a specific gene?

Accepted Answer

Northern blotting

Answer

Southern blotting

Answer

Western blotting

Answer

PCR

Question 28

In gene cloning experiments, which safety measure is paramount?

Accepted Answer

Maintaining sterile conditions throughout the procedure

Answer

Using only well-studied genes

Answer

Limiting gene cloning to plant sources

Answer

Ignoring ethical considerations

Question 29

Which enzyme cleaves DNA at specific palindromic sequences?

Accepted Answer

Restriction enzyme

Answer

DNA polymerase

Answer

Ligase

Answer

Reverse transcriptase

Question 30

Which restriction enzyme cuts at the palindromic sequence 5'-GGATCC-3'?

Accepted Answer

BamHI

Answer

HindIII

Answer

XbaI

Answer

EcoRI

Question 31

Which of these processes involves joining two DNA fragments together?

Accepted Answer

Ligation

Answer

Electroporation

Answer

Restriction digestion

Answer

Transformation

Question 32

What is the main function of a promoter in gene expression?

Accepted Answer

To initiate transcription

Answer

To enhance mRNA stability

Answer

To regulate gene expression timing

Answer

To terminate transcription

Question 33

Phosphorylation is an example of what type of modification?

Accepted Answer

Post-translational

Answer

Splicing

Answer

Co-translational

Answer

Pre-translational

Question 34

What is the key difference between constitutive and inducible promoters?

Accepted Answer

Constitutive promoters are always active, while inducible promoters require a specific signal to become active

Answer

Inducible promoters are always active, while constitutive promoters require a specific signal to become active

Question 35

Which ethical concern is primarily associated with the use of gene cloning in humans?

Accepted Answer

Potential for unintended consequences and impact on human well-being

Answer

Technical difficulties and low efficiency

Answer

High costs and limited accessibility

Question 36

Which restriction enzyme recognizes the palindromic sequence 5'-GAATTC-3'?

Accepted Answer

EcoRI

Answer

BamHI

Answer

XbaI

Answer

HindIII

Question 37

What is the purpose of creating sticky ends in gene cloning?

Accepted Answer

To facilitate the ligation of DNA fragments

Answer

To enhance transformation efficiency

Answer

To block exonuclease activity

Answer

To prevent nuclease degradation

Question 38

What is the role of DNA ligase in gene cloning?

Accepted Answer

To covalently link DNA fragments together

Answer

To amplify DNA fragments

Answer

To facilitate transformation of DNA into cells

Answer

To cleave DNA fragments

Question 39

What is the primary function of a promoter in gene expression?

Accepted Answer

To regulate the initiation of transcription

Answer

To enhance translation

Answer

To protect mRNA from degradation

Answer

To terminate transcription

Question 40

Which RNA polymerase is responsible for synthesizing messenger RNA (mRNA) in eukaryotic cells?

Accepted Answer

RNA polymerase II

Answer

T7 RNA polymerase

Answer

RNA polymerase I

Answer

RNA polymerase III

Question 41

What is the primary function of ribosomes in gene expression?

Accepted Answer

To translate mRNA into protein

Answer

To replicate DNA

Answer

To transcribe mRNA

Answer

To package DNA into chromosomes

Question 42

Which enzyme is specifically responsible for cleaving DNA at specific recognition sequences?

Accepted Answer

Restriction enzyme

Answer

Polymerase

Answer

Ligase

Question 43

What is the process of joining two DNA fragments called?

Accepted Answer

Ligation

Answer

Annealing

Answer

Transformation

Question 44

Which of the following is a commonly used selectable marker in gene cloning?

Accepted Answer

Antibiotic resistance gene

Answer

Promoter sequence

Answer

Green fluorescent protein gene

Answer

Reporter gene

Question 45

What is the process of generating a DNA molecule containing the coding sequence of a specific gene called?

Accepted Answer

Gene cloning

Answer

Gel electrophoresis

Answer

DNA sequencing

Answer

PCR

Question 46

Which of the following is not a step involved in gene cloning?

Accepted Answer

Protein purification

Answer

Selection

Answer

Transformation

Answer

Gene isolation

Question 47

How is the expression of a cloned gene achieved within a host cell?

Accepted Answer

Expression vector

Answer

Restriction enzyme

Answer

Polymerase chain reaction

Answer

Selectable marker

Question 48

Which technique is used to amplify a specific region of DNA?

Accepted Answer

PCR

Answer

Transformation

Answer

Ligation

Answer

Restriction digestion

Question 49

What is the process of producing a functional protein from a cloned gene known as?

Accepted Answer

Protein expression

Answer

Gene regulation

Answer

DNA replication

Answer

RNA transcription

Question 50

Which restriction enzyme is known to generate blunt ends in a DNA fragment?

Accepted Answer

SmaI

Answer

BamHI

Answer

HindIII

Answer

EcoRI

Question 51

In a gene cloning experiment, the primary purpose of using a vector with an antibiotic resistance gene is to:

Accepted Answer

Enable the selection of bacteria containing the recombinant plasmid.

Answer

Enhance the efficiency of DNA ligation.

Answer

Increase the stability of the cloned gene.

Question 52

Which technique is primarily used to introduce a recombinant plasmid into bacterial cells?

Accepted Answer

Transformation

Answer

Transduction

Answer

Transfection

Question 53

In the context of gene expression, the primary role of the TATA box in a gene's promoter region is to serve as a:

Accepted Answer

Binding site for RNA polymerase.

Answer

Enhancer of gene expression.

Answer

Initiation site for transcription.

Answer

Recognition site for restriction enzymes.

Question 54

In bacterial gene expression, the primary function of the Shine-Dalgarno sequence is to:

Accepted Answer

Align the ribosome with the start codon of mRNA.

Answer

Bind to the RNA polymerase.

Answer

Regulate the stability of mRNA.

Answer

Control the termination of transcription.

Question 55

When aiming to express a protein that is normally secreted from cells, which type of expression vector would be most appropriate?

Accepted Answer

Vector containing a signal sequence.

Answer

Vector with an antibiotic resistance gene.

Answer

Vector with a polyadenylation signal.

Answer

Vector with a strong promoter.

Question 56

Which of the following is NOT a widespread application of gene cloning and expression?

Accepted Answer

Developing new antibiotics.

Answer

Gene therapy.

Answer

Producing therapeutic proteins.