🌸Chapter 9
Biotechnology: Principles and Processes
(MCQs)
SECTION A: BASIC CONCEPTS OF
BIOTECHNOLOGY (1–15)
1.
Biotechnology primarily deals with:
a) Study of microorganisms
b) Use of living systems for human welfare
c) Study of life in space
d) None of these
✅ Answer: b
👉 Explanation: Biotechnology uses biological organisms, systems,
or processes for human benefit, such as producing medicines or improving crops.
2.
The two core techniques of modern biotechnology are:
a) Cell culture and cloning
b) Genetic engineering and bioprocess engineering
c) Hybridization and mutation
d) Tissue culture and fermentation
✅ Answer: b
👉 Explanation: Genetic engineering allows DNA manipulation;
bioprocess engineering ensures large-scale production under sterile conditions.
3.
The term “genetic engineering” means:
a) Production of new species
b) Manipulation of genetic material
c) Natural evolution
d) Artificial selection
✅ Answer: b
👉 Explanation: Genetic engineering directly manipulates DNA to
change the genetic makeup of organisms.
4.
In biotechnology, aseptic conditions are important to:
a) Increase cell mutation
b) Prevent contamination
c) Destroy host cells
d) Promote infections
✅ Answer: b
👉 Explanation: Aseptic or sterile conditions prevent
contamination by unwanted microbes.
5.
The first recombinant DNA molecule was constructed by:
a) Boyer and Cohen
b) Kary Mullis
c) Watson and Crick
d) Paul Berg
✅ Answer: a
👉 Explanation: Stanley Cohen and Herbert Boyer developed the
first recombinant DNA molecule using plasmid pSC101.
6.
Which field combines biology and technology?
a) Cytology
b) Biotechnology
c) Ecology
d) Morphology
✅ Answer: b
👉 Explanation: Biotechnology integrates biological science with
technology to create useful products.
7.
Genetic engineering involves:
a) Cross-breeding
b) Alteration of DNA sequence
c) Inducing mutation by radiation
d) None of these
✅ Answer: b
👉 Explanation: It includes insertion, deletion, or modification
of genes.
8.
Which organism is widely used in recombinant DNA experiments?
a) Bacillus subtilis
b) Escherichia coli
c) Rhizobium
d) Lactobacillus
✅ Answer: b
👉 Explanation: E. coli is preferred for gene cloning due
to its fast growth and well-known genetics.
9.
The term “Biotechnology” was coined by:
a) Karl Ereky
b) Kary Mullis
c) Edward Jenner
d) Paul Berg
✅ Answer: a
👉 Explanation: Karl Ereky (1919) coined the term biotechnology.
10.
Biotechnology aims at:
a) Using living organisms for production of useful substances
b) Studying diseases
c) Destroying microbes
d) Collecting data
✅ Answer: a
11.
Which is an example of biotechnology application?
a) Antibiotic production
b) Vaccine development
c) GM crops
d) All of these
✅ Answer: d
👉 Explanation: All are examples of applied biotechnology.
12.
The basic requirement for biotechnological processes is:
a) Genetic engineering
b) Bioprocess engineering
c) Both a and b
d) None
✅ Answer: c
13.
Biotechnology mainly uses which level of biological organization?
a) Cellular and molecular
b) Tissue and organ
c) Population
d) Ecosystem
✅ Answer: a
14.
“Recombinant DNA” means:
a) DNA from one organism
b) DNA combined from two sources
c) RNA combined with DNA
d) Mutated DNA
✅ Answer: b
15.
The first genetically modified product used commercially was:
a) Human insulin
b) Penicillin
c) Bt cotton
d) Golden rice
✅ Answer: a
SECTION B: TOOLS OF RECOMBINANT DNA
TECHNOLOGY (16–45)
16.
Which enzyme cuts DNA at specific sites?
a) Ligase
b) Restriction endonuclease
c) Polymerase
d) Transcriptase
✅ Answer: b
17.
Restriction enzymes are also known as:
a) Molecular knives
b) Molecular glue
c) Molecular scissors
d) Molecular markers
✅ Answer: c
18.
Restriction enzymes were discovered by:
a) Watson and Crick
b) Arber, Smith, and Nathans
c) Kary Mullis
d) Boyer and Cohen
✅ Answer: b
19.
Restriction enzymes recognize:
a) Specific RNA sequences
b) Specific DNA sequences
c) Proteins
d) Sugars
✅ Answer: b
20.
EcoRI cuts DNA at which site?
a) GAATTC
b) AATTCC
c) GATTAC
d) GGCCTT
✅ Answer: a
👉 Explanation: EcoRI recognizes 5′–GAATTC–3′ and cuts between G
and A.
21.
The overhanging ends produced by restriction enzymes are called:
a) Sticky ends
b) Blunt ends
c) Loose ends
d) Single ends
✅ Answer: a
22.
Which enzyme joins DNA fragments?
a) Ligase
b) Endonuclease
c) Polymerase
d) Transcriptase
✅ Answer: a
23.
The carrier DNA molecule used to transfer a gene is called:
a) Vector
b) Plasmid
c) Chromosome
d) Enzyme
✅ Answer: a
24.
The most commonly used vector in bacteria is:
a) pBR322
b) λ phage
c) pUC18
d) All of these
✅ Answer: d
25.
The origin of replication (Ori) in a vector is important for:
a) Protein synthesis
b) DNA replication
c) Mutation
d) Translation
✅ Answer: b
26.
pBR322 plasmid was developed by:
a) Boyer and Cohen
b) Bolivar and Rodriguez
c) Watson and Crick
d) Berg and Nathans
✅ Answer: b
27.
Selectable markers in a vector help in:
a) DNA replication
b) Identifying transformants
c) Transcription
d) None
✅ Answer: b
28.
Which of the following is a selectable marker?
a) Ampicillin resistance gene
b) Ori site
c) Restriction site
d) Promoter
✅ Answer: a
29.
The enzyme used to amplify DNA is:
a) DNA ligase
b) Taq polymerase
c) Helicase
d) DNAase
✅ Answer: b
30.
Taq polymerase is isolated from:
a) E. coli
b) Thermus aquaticus
c) Bacillus subtilis
d) Agrobacterium tumefaciens
✅ Answer: b
31.
Which of the following is not a cloning vector?
a) pUC19
b) λ phage
c) Ribosome
d) Cosmid
✅ Answer: c
32.
The enzyme used to remove RNA during DNA isolation is:
a) RNase
b) DNase
c) Protease
d) Lysozyme
✅ Answer: a
33.
The enzyme used to remove proteins during DNA isolation is:
a) Protease
b) RNase
c) DNase
d) Lipase
✅ Answer: a
34.
Which enzyme breaks the bacterial cell wall?
a) Lysozyme
b) Protease
c) Lipase
d) Cellulase
✅ Answer: a
35.
For isolation of plant DNA, which enzyme is used to degrade cell wall?
a) Cellulase
b) Lysozyme
c) Chitinase
d) Peptidase
✅ Answer: a
36.
The enzyme that cuts DNA within specific sites is:
a) Restriction endonuclease
b) Exonuclease
c) Ligase
d) Helicase
✅ Answer: a
37.
The function of DNA ligase is to:
a) Cut DNA
b) Join DNA fragments
c) Copy DNA
d) Remove RNA
✅ Answer: b
38.
What is the function of a plasmid?
a) To act as a vector
b) To synthesize proteins
c) To digest DNA
d) None
✅ Answer: a
39.
Sticky ends are useful because:
a) They prevent recombination
b) They help in gene joining
c) They destroy foreign DNA
d) They cause mutations
✅ Answer: b
40.
The term “bioreactor” refers to:
a) DNA synthesizer
b) Large vessel for culture growth
c) Centrifuge
d) PCR machine
✅ Answer: b
41.
Which of the following maintains aseptic conditions?
a) Sterilization
b) Incubation
c) Inoculation
d) Filtration
✅ Answer: a
42.
The enzyme used to synthesize DNA from RNA is:
a) Reverse transcriptase
b) Ligase
c) Restriction enzyme
d) Taq polymerase
✅ Answer: a
43.
The plasmid of Agrobacterium tumefaciens used for plant transformation
is:
a) Ti plasmid
b) Ri plasmid
c) pUC19
d) pBR322
✅ Answer: a
44.
Which of the following has both ampR and tetR genes?
a) pBR322
b) pUC8
c) λ phage
d) Cosmid
✅ Answer: a
45.
Competent cells can:
a) Take up foreign DNA
b) Synthesize DNA
c) Destroy plasmids
d) Mutate rapidly
✅ Answer: a
SECTION C: PROCESS OF RECOMBINANT
DNA TECHNOLOGY (46–80)
46.
The first step in recombinant DNA technology is:
a) Isolation of DNA
b) Ligation
c) Transformation
d) Screening
✅ Answer: a
47.
Pure DNA appears as:
a) Fine threads
b) Granules
c) Crystals
d) None
✅ Answer: a
48.
PCR stands for:
a) Polymerase Chain Reaction
b) Protein Chain Reaction
c) Peptide Chain Reaction
d) Polymerization of RNA
✅ Answer: a
49.
PCR was invented by:
a) Kary Mullis
b) Paul Berg
c) Boyer
d) Cohen
✅ Answer: a
50.
PCR involves repeated cycles of:
a) Denaturation, annealing, extension
b) Cooling, heating, freezing
c) Mutation, replication, translation
d) None
✅ Answer: a
51.
The enzyme used in PCR is:
a) Taq polymerase
b) Ligase
c) Helicase
d) RNA polymerase
✅ Answer: a
52.
Denaturation in PCR occurs at:
a) 95°C
b) 50°C
c) 72°C
d) 37°C
✅ Answer: a
53.
Annealing in PCR occurs at:
a) 50–60°C
b) 95°C
c) 72°C
d) 37°C
✅ Answer: a
54.
Extension in PCR occurs at:
a) 72°C
b) 37°C
c) 50°C
d) 25°C
✅ Answer: a
55.
The joining of DNA fragments is called:
a) Ligation
b) Translation
c) Hybridization
d) Mutation
✅ Answer: a
56.
In gene transfer using CaCl₂, the cell becomes:
a) Competent
b) Permeable
c) Mutated
d) Denatured
✅ Answer: a
57.
Biolistic or gene gun method is used in:
a) Plants
b) Animals
c) Bacteria
d) Fungi
✅ Answer: a
58.
Microinjection is used for:
a) Animal cells
b) Plant cells
c) Bacteria
d) Fungi
✅ Answer: a
59.
Electroporation involves:
a) Electric shock
b) Radiation
c) Chemicals
d) Lasers
✅ Answer: a
60.
The method used for selection of recombinants is:
a) Antibiotic resistance
b) Temperature
c) pH change
d) Color
✅ Answer: a
61.
In pBR322, insertion of foreign gene into tetR gene makes bacteria:
a) Sensitive to tetracycline
b) Resistant to tetracycline
c) Resistant to ampicillin
d) Sensitive to both
✅ Answer: a
62.
A bioreactor provides:
a) Optimum growth conditions
b) Electric current
c) Light energy
d) Pressure
✅ Answer: a
63.
Agitation in bioreactor is for:
a) Mixing and oxygen distribution
b) Cooling
c) Heating
d) Sampling
✅ Answer: a
64.
Sampling port in a bioreactor is used for:
a) Removing samples
b) Adding enzymes
c) Sterilization
d) Oxygen supply
✅ Answer: a
65.
The process of product purification after biosynthesis is:
a) Downstream processing
b) Upstream processing
c) Fermentation
d) Electrophoresis
✅ Answer: a
66.
Which of the following is part of downstream processing?
a) Purification
b) Packaging
c) Quality control
d) All
✅ Answer: d
67.
The final step in rDNA technology is:
a) Downstream processing
b) Ligation
c) Amplification
d) Cutting
✅ Answer: a
68.
The process used to increase the number of DNA copies is:
a) PCR
b) Electrophoresis
c) Ligation
d) Transformation
✅ Answer: a
69.
The product of PCR is:
a) Multiple copies of DNA
b) Proteins
c) RNA
d) Plasmid
✅ Answer: a
70.
DNA fragments can be visualized by:
a) Staining with ethidium bromide
b) Heating
c) Freezing
d) Centrifugation
✅ Answer: a
71.
DNA fragments are separated by:
a) Gel electrophoresis
b) Chromatography
c) Centrifugation
d) PCR
✅ Answer: a
72.
Agarose is obtained from:
a) Seaweeds
b) Bacteria
c) Plants
d) Fungi
✅ Answer: a
73.
In agarose gel electrophoresis, DNA moves toward:
a) Positive electrode
b) Negative electrode
c) Both
d) None
✅ Answer: a
👉 Explanation: DNA is negatively charged due to phosphate
groups, so it moves toward the positive electrode (anode).
74.
The smaller DNA fragments move:
a) Faster
b) Slower
c) Not at all
d) Randomly
✅ Answer: a
75.
The commonly used stain to see DNA in gel is:
a) Ethidium bromide
b) Methylene blue
c) Crystal violet
d) Safranin
✅ Answer: a
76.
The fluorescent color of ethidium bromide under UV light is:
a) Orange
b) Green
c) Red
d) Blue
✅ Answer: a
77.
DNA bands can be cut and extracted using:
a) Elution
b) Filtration
c) Centrifugation
d) Washing
✅ Answer: a
78.
The process of identifying recombinants from non-recombinants is:
a) Screening
b) Amplification
c) Transformation
d) Denaturation
✅ Answer: a
79.
The process of introducing rDNA into a host cell is:
a) Transformation
b) Transcription
c) Transduction
d) Translation
✅ Answer: a
80.
In transformation, bacteria uptake DNA through:
a) Cell membrane
b) Cell wall
c) Both
d) None
✅ Answer: c
SECTION D: APPLICATIONS AND
MISCELLANEOUS (81–100)
81.
The production of human insulin in E. coli is an example of:
a) Recombinant DNA technology
b) Mutation
c) Cloning
d) Hybridization
✅ Answer: a
82.
Which of the following is a product of rDNA technology?
a) Insulin
b) Growth hormone
c) Interferon
d) All
✅ Answer: d
83.
Large-scale production is done in:
a) Bioreactor
b) Petri dish
c) Test tube
d) Flask
✅ Answer: a
84.
The product obtained from bioreactor is:
a) Biomass
b) Desired protein
c) Both
✅ Answer: c
85.
Sterile air
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Perfect 👍 Continuing from Q86–100 (remaining
MCQs) from Chapter: Biotechnology – Principles and Processes (Class 12,
NCERT-based) — each with answer + short explanation for both CBSE
& NEET prep.
SECTION D (continued): APPLICATIONS
& CONCEPTUAL UNDERSTANDING (86–100)
86.
The air supplied in a bioreactor must be:
a) Sterile
b) Moist
c) Cold
d) Dusty
✅ Answer: a
👉 Explanation: Sterile air prevents microbial contamination
during large-scale culture.
87.
The process of maintaining sterile conditions in a bioreactor is known as:
a) Asepsis
b) Immunization
c) Filtration
d) Pasteurization
✅ Answer: a
👉 Explanation: Aseptic techniques ensure contamination-free
growth of recombinant microbes.
88.
The product obtained after downstream processing is:
a) Crude extract
b) Pure and formulated product
c) Contaminated sample
d) Waste
✅ Answer: b
👉 Explanation: Downstream processing includes purification and
formulation of final products like insulin or vaccines.
89.
The enzyme used to separate DNA fragments by size is:
a) None (it’s a physical process, not enzymatic)
b) Helicase
c) Ligase
d) DNase
✅ Answer: a
👉 Explanation: DNA fragments are separated by agarose gel
electrophoresis, which is not enzyme-dependent.
90.
In gel electrophoresis, movement of DNA fragments depends on:
a) Size of fragments
b) Shape of fragments
c) Sequence of bases
d) Color
✅ Answer: a
👉 Explanation: Smaller fragments move faster toward the positive
electrode.
91.
Which one of the following is not a step in recombinant DNA technology?
a) Isolation of DNA
b) Denaturation of proteins
c) Ligation of DNA fragments
d) Insertion into host
✅ Answer: b
👉 Explanation: Denaturation of proteins is not a defined step in
rDNA process; protein removal happens during DNA isolation.
92.
Which of the following statements is incorrect?
a) Restriction enzymes cut DNA at specific sites.
b) Ligase joins DNA fragments.
c) Taq polymerase synthesizes RNA.
d) Plasmid acts as vector.
✅ Answer: c
👉 Explanation: Taq polymerase synthesizes DNA, not RNA.
93.
Which enzyme acts as “molecular glue”?
a) Ligase
b) Restriction enzyme
c) Polymerase
d) Protease
✅ Answer: a
👉 Explanation: DNA ligase joins DNA fragments by forming
phosphodiester bonds.
94.
Which of the following enzymes is used to cut vector and foreign DNA at the
same site?
a) Same restriction endonuclease
b) Different endonuclease
c) Ligase
d) Polymerase
✅ Answer: a
👉 Explanation: Same restriction enzyme ensures compatible sticky
ends for ligation.
95.
The function of CaCl₂ in transformation is to:
a) Make bacterial cell wall permeable
b) Kill bacteria
c) Break DNA
d) Remove plasmid
✅ Answer: a
👉 Explanation: Ca²⁺ ions increase cell membrane permeability to
facilitate DNA uptake.
96.
The first human gene cloned was for:
a) Insulin
b) Growth hormone
c) Interferon
d) Somatotropin
✅ Answer: a
👉 Explanation: Human insulin gene was the first successfully
expressed gene in E. coli using recombinant DNA.
97.
Which of the following is not an example of a bioreactor?
a) Stirred-tank reactor
b) Sparged-tank reactor
c) Round-bottom flask
d) Air-lift reactor
✅ Answer: c
👉 Explanation: Flasks are used for small-scale cultures, not
industrial bioprocessing.
98.
Which of the following helps in maintaining the right pH in bioreactor?
a) Buffer and control system
b) Air supply
c) Agitator only
d) None
✅ Answer: a
👉 Explanation: Automated pH control system and buffer maintain
optimal conditions for culture growth.
99.
During downstream processing, product quality is checked in:
a) Quality control unit
b) Sampling port
c) Media tank
d) Gene gun
✅ Answer: a
👉 Explanation: After purification and formulation, quality
control ensures safety and efficacy before marketing.
100.
The correct sequence of steps in recombinant DNA technology is:
a) Isolation → Cutting → Ligation → Insertion → Screening → Culturing → Product
recovery
b) Insertion → Isolation → Ligation → Screening
c) Cutting → Insertion → Isolation → Amplification
d) None of these
✅ Answer: a
👉 Explanation: This is the correct stepwise flow as per NCERT:
Isolation → Restriction digestion → Amplification → Ligation → Insertion
into host → Screening → Culture → Downstream processing.
