Biotechnology: Principles and Processes Class 12 MCQ Questions With Answers
Biotechnology Principles And Processes MCQ Class 12 Question 1.
Name the enzymes ‘F and ‘Q’ that are involved in the processes given below
(A) Enzyme P-Exonuclease and Enzyme Q- Permease
(B) Enzyme P- Exonuclease and Enzyme Q- Ligase
(C) Enzyme P-Endonuclease and Enzyme Q- Permease
(D) Enzyme P-Restriction endonuclease and Enzyme Q- Ligase
Answer:
(C) Enzyme P-Endonuclease and Enzyme Q- Permease
Explanation :
Enzyme P is restriction endonuclease that cuts the DNA into fragments while enzyme join the two fragments.
Class 12 Biology Chapter 11 MCQ Question 2.
A biotechnologist wanted to create a colony of E.coli possessing the plasmid pBR322, sensitive to Tetracycline. Which one of the following restriction sites would he use to ligate a foreign DNA?
(A) Sal I
(B) Pvu I
(C) EcoRI
(D) Hind III
Answer:
(A) Sal I
Explanation :
When an alien gene is ligated at the Sal I site of tetracycline resistance gene in the vector pBR322, the recombinant lose tetra-cycline resistance due to insertion of the for-eign DNA.
Chapter 11 Biology Class 12 MCQs Question 3.
What is the criterion for DNA fragments movement on agarase gel during gel electrophoresis?
(A) The larger the fragment size, farther it moves
(B) The smaller the fragment size, farther it moves
(C) Positively charged fragment move to farther end.
(D) Negatively charged fragment do not move.
Answer:
(B) The smaller the fragment size, farther it moves
Explanation :
In agarose gel electrophoresis of DNA molecule smaller molecules travel faster then larger molecules. The movement of DNA fragment is inversely proportional to number of base pairs. Separation of DNA occurs by its length.
MCQ On Biotechnology Principles And Processes Chapter 11 Question 4.
An enzyme catalysing the removal of nucleotides from the ends of DNA is.
(A) endonuclease
(B) exonuclease
(C) DNA ligase.
(D) Hind-II.
Answer:
(B) exonuclease
Explanation:
Exomideases remove nucleotides from the ends of the DNA. Endonucleases make cuts al specific positions within the DNA. DNA ligase (also called genetic gum) is a sealing enyme w’hich is responsible for joining of two individual fragments of DNA, whereas Hind-II is the first discovered restriction endonuclease enzyme.
Biotechnology Principles And Processes Class 12 MCQ Chapter 11 Question 5.
The transfer of genetic material from one bacterium to another through the mediation of a vector-like virus is termed as
(A) transduction
(B) conjugation
(C) transformation
(D) translation
Answer:
(A) transduction
Explanation :
Transduction is the process by which genetic material (DNA) is transferred from one bacterium to another through the mediation of a vector, like virus. Bacterial conjugation is the process of transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. Transformation is the genetic alteration of a cell resulting I from the direct uptake and incorporation of exogenous genetic material (exogenous DNA) from its surroundings and taken up through the cell membranes. Translation is the process in which cellular ribosomes create proteins. It is a part of the process of gene expression.
Biotechnology Principles And Processes Class 12 MCQ Questions Question 6.
‘Restriction’ in Restriction enzyme refers to
(A) cleaving of phosphodiester bond in DNA by the enzyme.
(B) cutting of DNA at specific position only.
(C) prevention of the multiplication of bacteriophage in bacteria.
(D) All of the above
Answer:
(B) cutting of DNA at specific position only.
Explanation :
Restriction enzymes (also called molecular scissors) are responsible for cutting DNA. These enzymes belong to a class of enzymes called nucleases and are of two t types (i) Exonuclease which cut DNA at the ends and (ii) endonucleases which make cuts at specific positions within the DNA. The li term ‘restriction’ refers to the function of these enzymes in restricting the propagation of foreign DNA of bacteriophage in host bacterium, that is, cutting of DNA, at specific J position only.
Biotechnology Class 12 MCQ Chapter 11 Question 7.
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
Answer:
(B) transformed cells
Explanation :
Selectable markers help in identifying and eliminating rum transformants and selectively permitting the growth of the transformants. The normal E. coli cells donot carry resistance against any antibiotic. Competent bacterial cells arc made capable .to take foreign DNA with chemical treatment (e.g, calcium chloride).
MCQ Of Chapter 11 Biology Class 12 Question 8.
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.
Answer:
(C) uptake of DNA through transient pores in the bacterial cell wall.
Explanation :
In chemical method, the cell is treated with specific concentration of a divalent cation such as calcium which increases the pore size in cell wall. The cells are incubated with recombinant DNA on ice, followed by placing them briefly at 42°C and then putting it back on ice. This is called heat shock method. The bacteria now take up these recombinant DNA.
Biotechnology MCQ Class 12 Chapter 11 Question 9.
While isolating DNA from bacteria, which of the following enzymes is not used?
(A) Lysozyme
(B) Ribonuclease
(C) Deoxyribonuclease
(D) Protease
Answer:
(C) Deoxyribonuclease
Explanation :
Deoxyribonuclease enzyme is not used in the process of isolating DNA from bacteria as this enzyme causes the lysis of DNA molecules
MCQs Of Biology Class 12 Chapter 11 Question 10.
Which of the following bacteria is not a source of restriction endonuclease?
(A) Haemophilus influenzae
(B) Escherichia coli
(C) Agrobacterium tumefaciens
(D) Bacillius amyloli
Answer:
(C) Agrobacterium tumefaciens
Explanation :
Agrobacterium tumefaciens is a pathogen of several dicot plants. It delivers a piece of DNA known as T-DNA in the Ti plas-mid which transforms normal plant cells into tumour cells to produce chemicals required by pathogens. The restriction enzyme Eco Rl, is isolated from E. coli RY13. The first restriction enzymes Hind II was isolated from bacterium Haemophilus influenzas. The restriction enzyme Bam HI is isolated from Bacillus amyloli.
Biotechnology Principles And Processes MCQs Question 11.
The correct order of steps in polymerase chain reaction (PCR) is:
(A) Extension, Denaturation, Annealing
(B) Denaturation, Annealing, Extension
(C) Denaturation, Extension, Annealing
(D) Annealing, Extension, Denaturation
Answer:
(B) Denaturation, Annealing, Extension
Explanation :
A single PCR amplification cycle involves three basic steps : denaturation, annealing and extension. PCR stands for polymerase chain reaction in which multiple copies of the gene, for DNA of interest is synthesised in vitro.
MCQ Biotechnology Principles And Processes Question 12.
The process of separation and purification of expressed protein before marketing is called :
(A) Upstream processing
(B) Downstream processing
(C) Bioprocessing
(D) Post-production processing
Answer:
(B) Downstream processing
Explanation :
After completion of biosynthetic stage, the product has to be subjected through a series of processes before it is ready for marketing as a finished product. The processes include separation purification, which are collectively referred to as downstream processing.
MCQ On Biotechnology Class 12 Chapter 11 Question 13.
Stirred-tank bioreactors have been designed for.
(A) ensuring anaerobic conditions in culture vessel
(B) purification of product
(C) addition of preservatives to product
(D) availability of oxygen throughout process
Answer:
(D) availability of oxygen throughout process
Explanation:
The stirred lank bioreactor is well suited for large scale production of micro organism under asepLic condition for a number of days. It can be used easily in research laboratory and main advantage is an oxygen delivery system which provides oxygen without any interruption.
Biotechnology Principles And Processes MCQ Pdf Question 14.
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
Answer:
(D) Availability of ‘Thermostable’ DNA polymerase
Explanation :
The polymerase chain reaction (PCR) is a reaction in which amplification of specific DNA sequences is carried out in vitro. Such repeated amplification is achieved by the using thermostable DNA polymerase (isolated from a bacterium, Tlicrmus aquatints) envme which remains active and stable during high temperature and induced denaturation of doublestandard DNA.
Class 12 Biotechnology MCQ Chapter 11 Question 15.
Which of the following steps are catalysed by Taq polymerase in a PCR reaction?
(A) Denaturation of template
(B) Annealing of primers to template DNA
(C) Extension of primer end on the template DNA
(D) All of the above
Answer:
(C) Extension of primer end on the template DNA
Explanation :
In polymerase chain reaction, polymerisation or extension step is catalysed by taq polymerase enzyme. PCR is carried out in the following three steps (i) Denaturation The double-stranded DNA is denatured by applying high temperature of 95 for seconds. Each separated single strand now acts as template for DNA synthesis, (ii) Annealing Two sets of primers are added which anneal to the three ends of each separated strand, Primers act as initiators of replication, (iii)
Extension :
DNA polymerase extends the primers by adding nucleotides complementary to the template provided in the reaction. A thermostable DNA polymerase (Taq DNA polymerase) is used in the reaction which can tolerate the high temperature of the reaction. All these steps are repeated many times to obtain several copies of desired DNA.
Principles And Processes Of Biotechnology MCQ Question 16.
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
Answer:
(A) formation of phosphodiester bond between two DNA fragments.
Explanation:
DNA ligase (joining or sealing enzymes) are also called genetic gum. They join two individual fragments of double-stranded DNA by forming phosphodiester bonds between them. Thus, they help in sealing gaps in DNA fragments. Therefore, they act as a moil lecular glue.
Biology MCQs Class 12 Chapter 11 Question 17.
Which of the given statement 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.
Answer:
(D) Ethidium bromide stained DNA can be seen under exposure to UV light.
Explanation :
The separated DNA fragments (by the process of gel electrophoresis) are visu-alised after staining the DNA with ethidium bromide followed by exposure to ultraviolet (UV) radiation. These fragments are seen as orange coloured bands.
Biotechnology MCQ Chapter 11 Question 18.
Who among the following was awarded the Nobel Prize for the development of PCR technique?
(A) Herbert Boyer
(B) Hargovind Khurana
(C) Kary Mullis
(D) Arthur Komberg 0
Answer:
(C) Kary Mullis
12th Biology MCQ Questions Chapter 11 Question 19.
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 produces the same kind of sticky ends in different DNA Molecules.
Answer:
(C) It is isolated from viruses.
Explanation :
Restriction enzymes are a proloin produced by bacteria that cleaves DNA at specific sites. These are not found in viruses. They are present in bacteria to provide a Lvpe of defence mechanism (called the restriction modification system) against bacterial viruscs. They are of two types endonuclease and exonuclease. They are indispensable tools in recombinant DNA technology and genetic engineering.
Question 20.
Which of the following should be chosen for best yield if one were to produce a recombinant protein in large amounts?
(A) Laboratory flask of largest capacity
(B) A stirred-tank bioreactor without in-lets and outlets
(C) A continuous culture system
(D) Any of the above
Answer:
(C) A continuous culture system
Explanation :
If any protein encoding gene is expressed in a heterologous host, it is called recombinant protein. The cells harbouring cloned genes of interest may be grown on a small scale in the laboratory. The cultures may be used for extracting the desired protein and then purifying it by using different separation techniques. The cells can also be multiplied in a continuous culture system where the used me-dium is drained out from one side while fresh medium is added from the other to maintain the cells in their physiologically most active logexponential phase. This type of culturing method produces a larger biomass leading to higher yields of desired protein.
Assertion and Reason based MCQs
Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as :
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.
Question 1.
Assertion (A): EcoRl is restriction endonuclease enzyme.
Reason (R): Exonuclease removes nucleotides from the ends of DNA.
Answer:
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
Explanation : EcoRI is a restriction endonuclease enzyme. Exonuclease removes nucleotides from Ihe ends of DNA.
Question 2.
Assertion (A): Any fragment of DNA, when linked to the ori region, can be initiated to replicate.
Reason (R): Ori is a genetic sequence that acts as the initiation site for replication of DNA.
Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation :
The process of DNA replication begins at the ori sequence. The presence of ori in a DNA fragment makes it a selfreplicating molecule.
Question 3.
Assertion (A): Restriction enzymes belong to class nucleases.
Reason (R): Nucleases are of two kinds: Exo and endonucleases. Exonucleases remove nucleotides within the DNA.
Answer:
(C) Assertion (A) is true but reason (R) is false.
Explanation :
Nucleases are of two kinds exo and endonucleases, but exonucleases remove nucleotides from the ends of the DNA.
Question 4.
Assertion (A): E. coli having pBR322 with DNA insert at BamH I site cannot grow in medium containing tetracycline.
Reason(R): Recognition site for BamH I is present in TetR region of pBR322.
Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation :
pBR322 carries recognition sites for number of commonly used restriction enzymes. Recognition site for BamHl is present in their region i.e., region responsible for tetra cycling resistance. When an insert is added at the Bam recognition site the gene for tetras cocaine resistance becomes nonfunctional and the recombinant bacteria with plasmid pBR322 that has DNA insert at BamHl lose tetracycline resistance.
Question 5.
Assertion (A): It is essential to have few cloning sites in cloning vector.
Reason(R): It helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.
Answer:
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
Explanation:
It is essential to have few cloning sites in cloning vector. It is because, in order to link the alien DNA, the vector needs to have very few recognition sites for the commonly used restriction enzymes. Presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning. Also, the vector requires a selectable marker, which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.
Question 6.
Assertion (A): Thermus aquatics, is used in PCR technique.
Reason (R): It is a heat-stable DNA polymerase.
Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation :
Thermus aquaticus, is the source of DNA polymerase because it is a heatstable DNA polymerase.
Question 7.
Assertion (A): Agarose gel electrophoresis is used to check the progression of a restriction enzyme digestion.
Reason (R): Restriction enzyme digestions are performed by incubating purified DNA molecules with restriction enzymes.
Answer:
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
Explanation :
In Agarose gel electrophoresis, DNAs fragments cut by restriction enzyme can be arranged according to their sizes.
Question 8.
Assertion (A): DNA is positively charged molecule.
Reason (R): DNA moves towards the positive electrode (anode).
Answer:
(D) Assertion (A) is false but reason (R) is true.
Explanation :
DNA is a negatively charged molecule, hence it moves towards the positive electrode (anode).
Question 9.
Assertion (A): A primer is a small segment of DNA that binds to a complementary strand of DNA.
Reason(R): Primers are necessary to stop the functioning of DNA polymerase enzymes and, therefore, are necessary in polymerase chain reaction.
Answer:
(D) Assertion (A) is false but reason (R) is true.
Explanation :
A primer is a small segment of DNA that binds to a complementary strand of DNA. Primers are necessary to start the functioning of DNA polymerase enzyme and, therefore, are necessary in polymerase chain reaction.
Question 10.
Assertion (A): P-galactosidase coding sequence act as a selectable marker.
Reason (R): Enzyme galactosidase converts the galactose into lactose.
Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation :
Galactosidase is an enzyme that converts the galactose into lactose. This property makes this enzyme to be used as a selectable marker or reporter gene in molecular biology experiments. This property is exploited during the selection of recombinants from the non-recombinants.
Case-Based MCQs
Attempt any four sub-parts from each question, sub-part each carries 1 mark.
I. Read the following and answer questions from Question l. to Question 5. 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 endemicleases are Type 1 Type 11 and Type HI but only Type II restriction endonucleases are used in recombinant DNA technology. Restriction endonuclease EcoR I recognises the base sequence GAATTC In DNA duplex and cut strands between G and A.
Question 1.
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) both (A) and (C)
Explanation:
Type II enzymes are simpler and don’t require ATP as an energy source, unlike Type I and it makes cleavage or cut in both the strands of DNA molecule.
Question 2.
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) Mg2+ions
Explanation :
The restriction endonuclease binds to magnesium ions. One of these ions,binds to the phosphate grotygOtyhfrrc the cleavage occurs and is requirpftifofi aftlysis.
Question 3.
Restriction endonuclease was,isolated for the first time from a:
(A) plant cell
(B) animal cell
(C) prokaryotic cell
(D) germinal cell
Answer:
(C) prokaryotic cell
Explanation :
Restriction endonuclease was isolated for the first time from the bacterium Haemophilus influenzae (prokaryotic cell).
Question 4.
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) they cleave one or both the strands of DNA
Explanation :
Restriction endonucleases naturally targeL double stranded DNA and could cleave one or both strands of the same.
Question 5.
Which type of restriction endonucleases is used most in genetic engineering?
(A) Type I
(B) Type II
(C) Type m
(D) Type IV
Answer:
(B) Type II
Explanation :
Type I and Type III are complex and have only a limited role in genetic engi-neering. Type II restriction endonucleases are used mostly as the culling enzymes in gene cloning.
II. Read the following text and answer the following questions on the basis of the same:
The term biotechnology refers to the use of living organisms or their products to modify human health and their human environment. For example, ‘test- tube’ programme, synthesis of a gene or correcting a defective gene are all part of the biotechnology. The basis of the modern biotechnology are genetic engineering and maintenance of sterile conditions. Genetic engineering is the technique that alter the chemistry of genetic material i.e. DNA and RNA, then this genetic material is introduced into host organisms, which alter the phenotype of the host organism.
Question 1.
Discovery of ——- molecule made genetic engineering possible.
(A) Restriction exonuclease
(B) Restriction exonuclease
(C) Ribozyme
(D) DNA polymerase
Answer:
(B) Restriction exonuclease
Explanation :
Restriction endonucleus act as molecular sensor that gets the DNA from spe-cific nucleotide and gives desired fragment of DNA.
Question 2.
The recognition sequence of the first restriction enzyme isolated was ——– base pair long.
(A) four
(B) six
(C) five
(D) two.
Answer:
(B) six
Explanation :
ECoRI is isolated as first restriction that GAATAC nucleotide base pair.
Question 3.
The specific DNA sequence where EcoRI cuts is:
(A) GATTCG
(B) GAATTC
(C) GTTCAA
(D) TTCCAA.
Answer:
(B) GAATTC
Explanation :
HCoKl recognises GAATAC base pairs that cuts between G and A.
Question 4.
The cutting of DNA at specific locations became possible with the discovery of :
(A) Ligases
(B) Restriction enzymes
(C) Probes
(D) Selectable markers.
Answer:
(B) Restriction enzymes
Explanation :
Restriction enzymes are the molocular scissors that cuts the DNA from specific recognition site.
Question 5.
DNA fragments are :
(A) Positively charged
(B) Negatively charged
(C) Neutral
(D) Either positively or negatively charged depending on their size.
Answer:
(C) Neutral
Explanation :
DNA have PO as negative end So, DNA is negatively charged.
III. A schematic representation of polymerase chain reaction (PCR) up to the extension stage is given below.
Question 1.
Name the process ‘a’
(A) Termination
(B) Annealing
(C) Denaturation
(D) Extension
Answer:
(C) Denaturation
Explanation :
Denaturating is the first step of PCR which involves the breaking of phos-phate bond belwcent the DNA base pairs at temperature SCPC.
Question 2.
Identify ‘b’
(A) Termination
(B) Annealing primer
(C) Denaturation
(D) Extension
Answer:
(B) Annealing primer
Explanation :
The primer binds on the DNA that initiate the polymerisation with the help of lag polymerase enzyme at 72“C temperature.
Question 3.
Which of the following has popularized the PCR (Polymerase Chain Reaction) ?
(A) Easy availability of DNA template
(B) Availability of synthetic primers
(C) Availability of cheap deoxyribonucleotides
(D) Availability of thermostable DNA polymerase.
Answer:
(D) Availability of thermostable DNA polymerase.
Explanation :
Tag polymerase enzyme help to maintain the stability of DNA to be used repeatedly at high temperature in the PCR.
Question 4.
PCR technique is best for :
(A) DNA synthesis
(B) Protein amplification
(C) DNA amplification
(D) DNA ligation.
Answer:
(C) DNA amplification
Explanation:
PCR techniques is helpful to dctect very minute traces of virus or bacteria DNA and other multiple copies by A amplication.
Question 5.
Which among the following is not an application of PCR?
(A) ELISA
(B) Diagnosis of pathogens
(C) DNA fingerprinting
(D) In palaeontology.
Answer:
(A) ELISA
Explanation :
PCR techniques is used to identify traces of DNA but it can not diagnose pathogen or organism.