Students of class 12 Biology should refer to MCQ Questions Class 12 Biology Biotechnology Principles and Processes with answers provided here which is an important chapter in Class 12 Biology NCERT textbook. These MCQ for Class 12 Biology with Answers have been prepared based on the latest CBSE and NCERT syllabus and examination guidelines for Class 12 Biology. The following MCQs can help you to practice and get better marks in the upcoming class 12 Biology examination

Chapter 11 Biotechnology Principles and Processes MCQ with Answers Class 12 Biology

MCQ Questions Class 12 Biology Biotechnology Principles and Processes provided below have been prepared by expert teachers of grade 12. These objective questions with solutions are expected to come in the upcoming Standard 12 examinations. Learn the below provided MCQ questions to get better marks in examinations.

Question. Restriction endonuclease
(a) synthesizes DNA
(b) cuts the DNA molecues randomly
(c) cuts the DNA molecule at specific sites
(d) restricts the synethesis of DNA inside the nuclease

Question. Genetic engineering is possible, because
(a) we can cut DNA at specific sites by endonucleases like DNase I.
(b) restriction endonucleases purified from bacteria can be used in vitro. 
(c) the phenomenon of transduction in bacteria is well understood.
(d) we can see DNA by electron microscope.

Question. Stirred-tank bioreactors have been designed for
(a) addition of preservatives to the product
(b) purification of the product
(c) ensuring anaerobic conditions in the culture vessel
(d) availability of oxygen throughout the process

Question. Given below is a sample of a portion of DNA strand giving the base sequence on the opposite
strands. What is so special shown in it?
5′_____GAATTC_____3′
3′_____CTTAAG_____5′
(a) Replication completed
(b) Deletion mutation
(c) Start codon at the 5′ level
(d) Palindromic sequence of base pairs

Question. The linking of antibiotic resistance gene with the plasmid vector became possible with
(a) DNA polymerase
(b) exonucleases
(c) DNA ligase
(d) endonucleases

Question. Significance of ‘heat shock’ method in bacterial transformation is to facilitate 
(a) binding of DNA to the cell wall
(b) uptake of DNA through membrane transport proteins
(c) uptake of DNA through transient pores in the bacterial cell wall
(d) expression of antibiotic resistance gene 402 Xam idea Biology–XII

Question. The role of DNA ligase in the construction of a recombinant DNA molecule is
(a) formation of phosphodiester bond between two DNA fragments
(b) formation of hydrogen bonds between sticky ends of DNA fragments
(c) ligation of all purine and pyrimidine bases
(d) None of the above

Question. Which of the given statements is correct in the context of observing DNA separated by agarose gel electrophoresis?
(a) DNA can be seen in visible light
(b) DNA can be seen without staining in visible light
(c) Ethidium bromide stained DNA can be seen in visible light
(d) Ethidium bromide stained DNA can be seen under exposure to UV light

Question. Which of the following is not a characterstic of the plasmids ?
(a) Extranuclear
(b) Single-stranded
(c) Independent replication
(d) Circular DNA

Question.DNA fragments generated by the restriction endonuclease in a chemical reaction can be separated by
(a) Gel electrophoresis
(b) Restriction mapping
(c) Centrifugation
(d) PCR

Question. There is a restriction endonuclease called Eco RI. What does “co” part in it stand for?
(a) Colon
(b) Coelom
(c) Coenzyme
(d) Coli

Question. The transfer of genetic material from one bacterium to another through the mediation of a viral vector is termed as:
(a) transduction
(b) conjugation
(c) transformation
(d) translation

Question. Which of the following is not required in the preparation of a recombinant DNA molecule? 
(a) Restriction endonuclease
(b) DNA ligase
(c) DNA fragments
(d) E.coli

Question. While isolating DNA from bacteria, which of the following enzymes is not required? 
(a) Lysozyme
(b) Ribonuclease
(c) Deoxyribonuclease
(d) Protease

Question. Agarose extracted from sea weeds is used in
(a) spectrophotometry
(b) tissue culture
(c) PCR
(d) gel electrophoresis

Question. An enzyme catalysing the removal of nucleotides from the ends of DNA is
(a) endonuclease
(b) exonuclease
(c) DNA ligase
(d) Hind-II

Question. Which of the following has popularised the PCR (polymerase chain reactions)? 
(a) Easy availability of DNA template
(b) Availability of synthetic primers
(c) Availability of cheap deoxyribonucleotides
(d) Availability of ‘Thermostable’ DNA polymerase

Question. Select the correct sequence of processing of PCR.
(a) Extension, primer annealing, denaturation
(b) Denaturation, primer annealing, extension
(c) Denaturation, extension, primer annealing
(d) Primer annealing, denatturatiotn, extension

Question. Which of the following is/are used in recombinant DNA technology ?
1. Agarose gel
2. Restriction endonuclease
3. Plasmid vector
4. Ethidium bromide
(a) 1 and 2
(b) 2 and 3
(c) 3 and 4
(d) All of these

Question. An antibiotic resistance gene in a vector usually helps in the selection of
(a) competent cells
(b) transformed cells
(c) recombinant cells
(d) none of the above

Question. Which of the following steps are catalysed by Taq DNA polymerase in a PCR reaction? 
(a) Denaturation of template DNA
(b) Annealing of primers to template DNA
(c) Extension of primer end on the template DNA
(d) All of the above

Question. A bacterial cell was transformed with a recombinant DNA molecule that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be:
(a) Human gene may have intron which bacteria cannot process
(b) Amino acid codons for humans and bacteria are different
(c) Human protein is formed but degraded by bacteria
(d) All of the above 

Question. Restriction-modification systems of bacteria exist to
(a) protect bacteria from invading foreign DNA.
(b) promote conjugation.
(c) help the bacterial chromosome to replicate.
(d) encourage recombination of new genetic material.

Question. In genetic engineering, the antibiotics are used
(a) as selectable markers.
(b) to select healthy vectors.
(c) to keep the cultures free of infection.
(d) as sequences from where replication starts.

Question. In genetic engineering, the antibiotics are used
(a) as selectable markers
(b) to keep the cultures free of inection
(c) to select healthy vectors
(d) as sequence from where replication starts

Question. Which of these is not correctly matched?
(a) Gene gun—biolistic gun
(b) Plasmids—extrachromosomal DNA
(c)  DNA ligase—biological scissors
(d) Bacteriophages—viruses

Question. Which of the following statements does not hold true for restriction enzyme?
(a) It recognises a palindromic nucleotide sequence
(b) It is an endonuclease
(c) It is isolated from viruses
(d) It can produce the same kind of sticky ends in different DNA molecules

Question. DNA fragments generated by the restriction endonucleases in a chemical reaction can be separated by
(a) polymerase chain reaction
(b) electrophoresis
(c) restriction mapping
(d) centrifugation

Question. The first restriction endonuclease reported was
(a) Hind II
(b) EcoRI
(c) Hind III
(d) BamHI

Question. Which one of the following is a correct statement regarding DNA polymerase used in PCR ?
(a) It is used to ligate introduced DNA in recipient cell.
(b) It serves as a selectable marker.
(c) It is isolated from a virus.
(d) It remains active at high temperature induced denaturation of double stranded DNA

Question. Restriction enzymes belong to a larger class of enzymes, which is called as
(a) ligases
(b) kinases
(c) nucleases
(d) polymerases

Question. The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of
(a) insertional inactivation of alphaga-lactosidase in nonrecombinant bacteria.
(b) insertional inactivation of alpha-galactosidase in recombinant bacteria.
(c) inactivation of glycosidase enzyme in recombinant bacteria.
(d) non-recombinant bacteria containing betagalactosidase.

Question. Which of the following enzyme is used in case of fungus to cause release of DNA along with other macromolecules ?
(a) Lysozyme
(b) Cellulase
(c) Chitinase
(d) Amylase

Question. Plasmid present in bacterial cells are
(a) circular double helical DNA molecules.
(b) linear double helical DNA molecules.
(c) circular double helical RNA molecules.
(d) linear double helical RNA molecules.

Question. During isolation of DNA, addition of which of the following causes precipitation of purified DNA ?
(a) Chilled ethanol
(b) Ribonuclease enzyme
(c) DNA polymerase
(d) Proteases 

Question. Which statement about restriction enzymes is incorrect ?
(a) Restriction enzymes cut DNA at specific sequence called recognition sites.
(b) A restriction enzyme always cut DNA to leave the same sequence at the ends.
(c) Some restriction enzymes cut the two DNA strands at slightly different points within their recognition site to make a ‘sticky’ end.
(d) Restriction enzymes are exonucleases rather than endonucleases.

Question. Which of the following statement is incorrect ?
(a) Hind-II always cuts DNA molecules at a particular point by recognizing a specific sequence of 4 base pairs.
(b) Besides Hind-II, today we know more than 900 restriction enzymes.
(c) The name Eco-RI comes from Escherichia coli-13.
(d) Restriction endonuclease are used in genetic engineering to form recombinant molecules of DNA.

Question. Molecular probes used for identification of recombinant clone carrying the desired DNA insert can be
(i) denatured double stranded DNA probes.
(ii) double stranded RNA probes.
(iii) protein probes.
(iv) single stranded DNA probes.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) All of these

Question. Restriction endonucleases
(a) are enzymes that process pre-RNA’s.
(b) are enzymes that degrade DNA.
(c) protect bacterial cells from viral infection.
(d) None of the above

Question. The same basic techniques can be used to analyze the DNA from species as diverse as bacteria and humans because:
(a) all cells are identical.
(b) every organism has the same amount of DNA.
(c) the DNA sequences of all organisms are the same.
(d) DNA has a consistent structure in all organisms

Question. Imagine a gel through which DNA fragments have moved in response to an applied electrical current. The band on this gel that is farthest from the top (that is, from the place e the DNA fragments were added to the “well”) represents the
(a) shortest fragments of DNA.
(b) longest fragments of DNA.
(c) restriction enzyme used to cut the DNA into fragments.
(d) ligase used to bind the DNA fragments together.

Question. A biologist intends to use a polymerase chain reaction to perform a genetic task. The biologist probably is trying to
(a) discover new genes.
(b) clone a gene.
(c) cut DNA into many small fragments.
(d) isolate DNA from a living cell.

Question. Which of the following is known as specific molecular scissors?
(a) Ligase
(b) Helicase
(c) Restriction endonuclease
(d) DNA polymerase

Question. The linking of antibiotic resistance gene with the plasmid vector became possible with
(a) DNA ligase
(b) endonucleases
(c) DNA polymerase
(d) exonucleases

Question. In agarose gel electrophoresis, DNA molecules are separated on the basis of their 
(a) charge only
(b) size only
(c) charge to size ratio
(d) All of the above

Question. The most important feature in a plasmid to be used as a vector is
(a) origin of replication (ori)
(b) presence of a selectable marker
(c) presence of sites for restriction endonuclease
(d) its size

Question. Which of the following is a plasmid?
(a) pBR 322
(b) Bam H I
(c) Sal I
(d) Eco RI

Question. Which of the following is not correct about pBR 322 vector ?
(a) It was constructed by using DNA derived from naturally occurring plasmids of E coli.
(b) It has two drug resistance genes-tetR and ampR.
(c) It was developed by Bolivar and Rodriguez.
(d) Selectable markers present in it can differentiate recombinants from non-recombinants on the basis of their inability to produce colour in the presence of chromogenic substrate

Question. Given below is a sample of a portion of DNA strand giving the base sequence on the opposite strands. What is so special shown in it?
5′_____ GAATTC′ _____ 3′
3′_____ CTTAAG _____ 5′
(a) Replication completed
(b) Deletion mutation
(c) Start codon at the 5′ end
(d) Palindromic sequence of base pairs.

Question. Agarose extracted from sea weeds is used in
(a) spectrophotometry
(b) tissue culture
(c) PCR
(d) gel electrophoresis.

Question. In genetic engineering, a DNA segment (gene) of interest, is transferred to the host cell through a vector. Consider the following four agents (i-iv) in this regard and select the correct option about which one or more of these can be used as a vector/vectors.
(i) Bacterium
(ii) Plasmid
(iii) Plasmodium
(iv) Bacteriophage
(a) (i), (ii) & (iv)
(b) (i) only
(c) (i) & (iii)
(d) (ii) & (iv)

Question. Which one of the following is used as vector for cloning genes into higher organisms?
(a) Baculovirus
(b) Salmonella typhimurium
(c) Rhizopus nigricans
(d) Retrovirus

Question. DNA precipitation out of a mixture of biomolecules can be achieved by treatment with
(a) chilled chloroform
(b) isopropanol
(c) chilled ethanol
(d) methanol at room temperature.

Question. Which one of the following equipments is essentially required for growing microbes on a large scale, for industrial production of enzymes?
(a) Bioreactor
(b) BOD incubator
(c) Sludge digester
(d) Industrial oven

Question. The process of separation and purification of expressed protein before marketing is called
(a) downstream processing
(b) bioprocessing
(c) postproduction processing
(d) upstream processing.

Question. Stirred-tank bioreactors have been designed for
(a) purification of product
(b) addition of preservatives to the product
(c) availability of oxygen throughout the process
(d) ensuring anaerobic conditions in the culture vessel.

Question. Match the items in column I with their uses in column II and choose the right option.

Column I	Column II
A. Bacillus thuringiensis	(i) Restriction endonuclease
B. Agrobacterium tumefaciens	(ii) Thermostable DNA polymerase
C. Thermus aquaticus	(iii) Insecticidal protein
D. Escherichia coli	(iv) Ti plasmid

(a) A-(iii), B-(iv), C-(i), D-(ii)
(b) A-(ii), B-(i), C-(iv), D-(iii)
(c) A-(iii), B-(iv), C-(ii), D-(i)
(d) A-(i), B-(iv), C-(ii), D-(iii)

Question. In vitro clonal propagation in plants is characterised by
(a) PCR and RAPD
(b) northern blotting
(c) electrophoresis and HPLC
(d) microscopy.

Question. Identify the desirable characteristics for a plasmid used in rDNA technology from the following.
A. Ability to multiply and express outside the host in a bioreactor
B. A highly active promoter
C. A site at which replication can be initiated
D. One or more identifiable marker genes
E. One or more unique restriction sites
(a) A, C, D and E only (b) A, C and E only
(c) B, C, D and E only (d) B, C and E only

Question. Match the entries in column I with those of column II and choose the correct answer.

Column I	Column II
A. Restriction endo- nucleases	(p) Kohler and Milstein
B. Polymerase chain reaction	(q) Alec Jeffreys
C. DNA fingerprinting	(r) Arber
D. Monoclonal antibodies	(s) Karry Mullis

(a) A – (r), B – (s), C – (q), D – (p)
(b) A – (r), B – (q), C – (s), D – (p)
(c) A – (q), B – (r), C – (s), D – (p)
(d) A – (q), B – (s), C – (r), D – (p)

Question. The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?
(a) B – Denaturation at a temperature of about 98°C separating the two DNA strands.
(b) A – Denaturation at a temperature of about 50°C.
(c) C – Extension in the presence of heat stable DNA polymerase.
(d) A – Annealing with two sets of primers.

Question. Which one is a true statement regarding DNA polymerase used in PCR?
(a) It is used to ligate introduced DNA in recipient cells.
(b) It serves as a selectable marker.
(c) It is isolated from a virus.
(d) It remains active at high temperature.

Question. PCR and restriction fragment length polymorphism are the methods for
(a) study of enzymes
(b) genetic transformation
(c) DNA sequencing
(d) genetic fingerprinting.

Question. The term, ‘Southern Blotting’ refers to
(a) transfer of DNA fragments from in vitro cellulose membrane to electrophoretic gel
(b) attachment of probes to DNA fragments
(c) transfer of DNA fragments from electrophoretic gel to nitrocellulose sheet
(d) comparison of DNA fragments from two sources.

Case-based MCQs

Read the following and answer questions given below :
Restriction endonuclease was isolated for the first time by W. Aber in 1962 in bacteria. Restriction endonucleases cut the DNA duplex at specific points therefore they are also called as molecular scissors or biological scissors. Three types of restriction endonucleases are Type I, Type II and Type III. Restriction endonuclease EcoR I recognises the base sequence GAATTC in DNA duplex and cut strands between G and A.

Question. Which of the following ions are used by restriction endonucleases for restriction?
(a) Mg²+ ions
(b) Mn2+ ions
(c) Na+ions
(d) K+ions
Answer : (a)

Question. Which type of restriction endonucleases is used mostly in genetic engineering?
(a) Type I
(b) Type II
(c) Type III
(d) Type IV
Answer : (b)

Question. Restriction endonuclease was isolated for the first time from a :
(a) Plant cell
(b) Animal cell
(c) Prokaryotic cell
(d) Germinal cell
Answer : (c)

Question. Only type II restriction enzymes are used in gene manipulation because :
(a) ATP is not required for cleaving.
(b) It consists of three different subunits.
(c) It makes cleavage or cut in both the strands of DNA molecule.
(d) Both (a) and (c).
Answer : (d)

Question. Restriction endonucleases are also called as molecular or biological scissors because :
(a) They cleave base pairs of DNA only at their terminal ends.
(b) They cleave one or both the strands of DNA.
(c) They act only on single stranded DNA.
(d) None of these.
Answer : (b)

We hope the above multiple choice questions for Class 12 Biology for Chapter 11 Biotechnology Principles and Processes provided above with answers based on the latest syllabus and examination guidelines issued by CBSE, NCERT and KVS are really useful for you. Biotechnology Principles and Processes is an important chapter in Class 12 as it provides very strong understanding about this topic. Students should go through the answers provided for the MCQs after they have themselves solved the questions. All MCQs have been provided with four options for the students to solve. These questions are really useful for benefit of class 12 students. Please go through these and let us know if you have any feedback in the comments section.