CBSE Questions for Class 12 Medical Biology Biotechnology: Principles And Processes Quiz 8 - MCQExams.com

To carry out a polymerase chain reaction (PCR), one must have the catalytic DNA polymerase and
  • a blueprint or gene map of the sequence one wish to copy
  • a number of primers from either side of the target DNA in order to get the polymerase replication process- going
  • a DNA synthesizer machine
  • a DNA probe
Which of the following tools of recombinant DNA technology is incorrectly paired with its use?
  • Reverse transcriptase-production of.cDNA from mRNA
  • DNA polymerase-used in polymerase chain reaction to amplify section of DNA
  • DNA ligase-enzyme that cuts DNA, creating the sticky ends of restriction fragments
  • Restriction enzyme-production of RFLPs
DNA fragments result when .......... cut DNA molecules at specific sites.
  • RELPs
  • DNA probes
  • restriction enzymes
  • DNA polymerase
Which of the following statements is untrue about restriction enzymes
  • They are made by bacteria and viruses
  • The first one was isolated in 1970, and thereafter hundreds of different ones have been isolated and purified
  • They produce single-stranded complementary ends that can join together two different DNA strands
  • Each enzyme cuts DNA at a different specific base sequence
The sticky ends of a fragmented DNA molecule are made up of ________.
  • Calcium salts
  • Endonuclease enzyme
  • Unpaired bases
  • Methyl groups
The restriction enzyme responsible for the cleavage of following sequence is ______________.
927859_79e2104b17b3457bab8e05658e878a27.PNG
  • EcoRI
  • Hindll
  • BamHI
  • EcoRII
Which of the following statements is not correct regarding EcoRI restriction endonuclease enzyme?
  • It is isolated from Escherichia coli RY13
  • Its recognition sequence is 5'-GAATTC-3'

    3'-CTTAAG-5'
  • It produces complementary blunt ends
  • None of these
Study the given figure carefully and select the incorrect statements regarding this.(i) It represents a typical agarose gel electrophoresis in which lane 1 contains undigested DNA(ii) Smallest DNA bands are formed at A and largest DNA bands are formed at B(iii) The separated DNA fragments can be visualized after staining in the visible light(iv) The separated DNA bands are cut out from the agarose gel and extracted from the gel piece. This step is known as elution.

927990_c7ac9c4676bb449481dd375992c31e71.PNG
  • (i) and (ii)
  • (ii) and (iii)
  • (ii) and (iv)
  • (i) and (iv)
Gel electrophoresis is used for
  • Construction of recombinant DNA by joining with cloning vectors
  • Isolation of DNA molecules
  • Cutting of DNA into fragments
  • Separation of DNA fragments according to their size
Which of the following is not a cloning vector?
  • Cosmid
  • pBR322
  • Whose origin supports high copy number
  • Which has only one restriction site
If a plasmid vector is digested with EcoRI at a single site, then
  • One sticky end will be produced
  • Two sticky ends will be produced
  • Four sticky ends will be produced
  • Six sticky ends will be produced
Gel electrophoresis is a
  • Technique of separation of charged molecules under the influence of magnetic field
  • Technique of incorporation of DNA molecules into the cell through transient pores made due to electrical impulses
  • Technique of separation of DNA fragments through the pores of agarose gel under the influence of electric field
  • Technique of separation and purification of gene products
In recombinant DNA technology, a plasmid vector is cleaved by ________________.
  • Modified DNA ligase
  • A heated alkaline solution
  • The same enzyme that cleaves the donor DNA
  • The different enzyme than that cleaves the donor DNA
If you want to recover many copies of the target DNA, you will choose a vector __________________.
  • Which does not have origin of replication
  • Which has antibiotic resistance gene
  • Whose origin supports high copy number
  • Which has only one restriction site
Which of the following tools of recombinant DNA technology is incorrectly paired with its use?
  • EcoRI - Production of sticky ends
  • DNA ligase - Multiplication of rDNA molecules
  • Ori- Copy number
  • Selectable marker - Identification of transformants
How many fragments will be generated on the digestion of a closed circular DNA molecule with a restriction enzyme having six recognition sites on the DNA?
  • 5
  • 7
  • 6
  • 9
Having become an expert on gel electrophoresis, you are asked to examine a gel for a colleague. Where would you find the smallest segments of DNA?
  • Near the positive electrode, farthest away from the wells
  • Near the negative electrode, close to the wells
  • Near the negative electrode, farthest away from the wells
  • Near the middle, they tend to slow down after the first few minutes
Read the given statements and select the correct option.
Statement 1 : Both bacteria and yeast multiply very fast to form huge populations which express the desired gene.
Statement 2 : In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeast (eukaryotes).
  • Both statements 1 and 2 are correct
  • Statement 1 is correct but statement 2 is incorrect
  • Statement 1 is incorrect but statement 2 is correct
  • Both statements 1 and 2 are incorrect
Which of the following is not a characteristic of pBR322 vector?
  • It was the first artificial cloning vector constructed in 1977 by Boliver and Rodriguez
  • It is the most widely used, versatile and easily manipulated vector
  • It has two antibiotic resistance genes $$tet^R$$ and $$amp^R$$
  • It does not have restriction site for SaII
If a person obtains transformants by inserting a recombinant DNA within the coding sequence of enzyme -galactosidase, he will separate out recombinants from non-recombinants by which of the following observations?
  • Non-recombinant colonies do not produce any colour whereas recombinants give blue coloured colonies
  • Recombinant colonies do not produce any colour whereas non-recombinants give blue coloured colonies
  • Recombinants and non-recombinants both produce blue coloured colonies
  • No colonies are formed due to insertional inactivation
An advantage of using yeasts rather than bacteria as recipient cells for the recombinant DNA of eukaryotes is that yeasts can ______________.
  • Produce restriction enzymes
  • Excise introns from the RNA transcript
  • Remove methyl groups
  • Reproduce more rapidly
In the process of insertional inactivation ________________.
  • A recombinant DNA is inserted within the coding sequence of enzyme -galactosidase, resulting in inactivation of the enzyme
  • A recombinant DNA is inserted within the coding sequence of proteins involved in the replication of the plasmid
  • A recombinant DNA is inserted within the recognition site for EcoRI
  • None of the above
Identify A, B, C and D in the given figure of E. coli cloning vector pBR322 and select the correct option
928004_008d6aab3b654ad0adaf8c9693240092.PNG
  • A - Hindi

    B - EcoRI

    C- $$amp^R$$

    D - ori
  • A - Hindi

    B - BamHI

    C- $$kan^R$$

    D - $$amp^R$$
  • A - BamHI

    B - Pstl

    C - Ori

    D - $$amp^R$$
  • A - EcoRI

    B - BamHI

    C - $$amp^R$$

    D - ori
pBR322 was the first artificial cloning vector to be constructed. What does "BR" stands for?
  • Bacteriophage and Recombinant
  • Boliver and Rodriguez
  • Boyer and Replicative
  • None of these
Which of the following statements are correct?

(i) Restriction enzymes cut the strand of DNA a little away from the centre of the palindrome site, but between the same two bases on the opposite strands.
(ii) Hind II always cuts DNA molecules at a particular point by recognising a specific sequence of six base pairs.
(iii) Separated DNA fragments cannot be visualised without staining on an agarose gel electrophoresis.
(iv) Ori is the sequence responsible for controlling the copy number.
(v) DNA is a positively charged molecule.
  • (i), (iii) and (v)
  • (i), (ii), (iii) and (iv)
  • (iii), (iv) and (v)
  • (i), (ii), (iii), (iv) and (v)
What will be the effect if pBR322, a cloning vector does not carry 'ori site?
  • Sticky ends will not produce
  • Transformation will not take place
  • The cell will transform into a tumour cell
  • Replication will not take place
In pBR322, tetracycline resistance gene ($$tet^R$$) has recognition site for which of the following restriction endonuclease?
  • HindIII
  • BamHl
  • EcoRI
  • Pstl
Precipitates of purified DNA after the addition of chilled ethanol can be seen as a collection of fine threads in suspension. This process is referred as _____________.
  • DNA transformation
  • DNA ligation
  • DNA spooling
  • DNA duplication
Which of the following bacteria is used as a vector for plant genetic engineering?
  • Agrobacterium tumefaciens
  • Bacteriophages
  • Thermus aquaticus
  • Pyrococcus furiosus
The polymerase chain reaction is a technique used for ____________.
  • Amplification of DNA
  • Amplification of enzymes
  • Amplification of proteins
  • All of these
The correct sequence of making a cell competent is
  • Treatment with divalent cations, incubation of cells with recombinant DNA on ice, heat shock ($$42^0$$C) again placing on ice.
  • Heat shock ($$42^0$$C), incubation of cells with recombinant DNA on ice treatment with divalent cations placing on ice.
  • Treatment with divalent cations, placing on ice incubation of cells with recombinant DNA on ice heat shock ($$42^0$$C).
  • Incubation of cells with recombinant DNA on ice, heat shock ($$42^0$$C) treatment with divalent cations placing on ice
Process used for amplification or multiplication of DNA in DNA fingerprinting is
  • Polymerase chain reaction
  • Southern blotting
  • Northern blotting
  • None of these
During isolation of genetic material, the chemical used to precipitate out the purified DNA is
  • Bromophenol blue
  • Chilled ethanol
  • Ethidium bromide
  • Both A and C
In the isolation of DNA, removal of protein and RNA is carried out by enzymes _____ and _________ respectively.
  • Lysozyme, Ribonuclease
  • Protease, Cellulase
  • Protease, Ribonuclease
  • Ribonuclease, Chitinase
Enzyme' Taq polymerase' used in PCR, has been isolated from bacterium _________________.
  • Agrobacterium tumefaciens
  • Thermus aquaticus
  • Streptomyces albus
  • Escherichia coli
Micro-injection is a method used to
  • Produce sticky ends of DNA
  • Provide protection against pathogen
  • Purify the DNA
  • Inject recombinant DNA into the nucleus of an animal cell
In biolistic method of gene transfer, the microparticles coated with foreign DNA are bombarded into target cells at a very high velocity. These microparticles are made up of
  • Silver or Tungsten
  • Arsenic or Silver
  • Gold or Tungsten
  • None of these
Read the following statements and select the incorrect ones.

(i) When the transformed cells on agar plates containing ampicillin are spread, both transformed and untransformed cells will grow.
(ii) Restriction enzymes are used in isolation and separation of DNA from other macromolecules.
(iii) Downstream processing is one of the steps of rDNA technology.
(iv) Disarmed pathogen vectors are also used in the transfer of rDNA into the host.
  • (ii) and (iii)
  • (iii) and (iv)
  • (i) and (iii)
  • (i) and (ii)
Given table gives an account of differences between PCR and gene cloning. Which of the, following points shows the incorrect difference?


 

Parameter

PCR

Gene cloning


1

Efficient

More

Less


2

Apparatus Requirement

DNA

Restriction enzyme, ligase, vector, bacterial cell


3

Manipulation

In vitro

In vitro and in vivo


4

Cost

More

Less


5

Automation

Yes

No


6

Error probability

Less

More


7

Time for a typical experiment

2-4 days

4 hours


8

Application

More

Less

  • 1 and 3
  • 4 and 6
  • 4 and 7
  • 4, 7 and 8
Which of the following statements are correct for the enzyme Taq polymerase?

(i) It remains active during the high temperature-induced denaturation of dsDNA.
(ii) It requires primers for carrying out the process of polymerisation.
(iii) It synthesizes the RNA region between the primers, using $$dNTPs$$ and $$Mg^{2+}$$ _______________.
  • (i) and (ii)
  • (ii) and (iii)
  • (i), (ii) and (iii)
  • None of these
Which of the following is not used to transfer the recombinant DNA into the host?
  • Micro-injection method
  • Gene gun method
  • Bioreactors
  • Disarmed pathogen vectors
If a recombinant DNA bearing gene for resistance to antibiotic ampicillin is transferred to E.coli cells, the host cells become transformed into ampicillin-resistant cells. If such bacteria are transferred on agar plates containing ampicillin, only transformants will grow and the untransformed recipient cells will die. The product produced by transformant bacteria that digests the ampicillin antibiotic is called as - 
  • Selectable marker
  • Recombinant protein
  • Cloning site
  • Chemical scalpels
In a polymerase chain reaction, temperature required for the steps (i) Denaturation,(ii) Annealing, and (iii) Extension are respectively.
  • (i) $$94^o$$$$C$$ (ii) $$40^o$$$$C$$ (iii) $$72^o$$$$C$$
  • (i) $$40^o$$$$C$$ (ii) $$72^o$$$$C$$ (iii) $$94^o$$$$C$$
  • (i) $$94^o$$$$C$$ (ii) $$72^o$$$$C$$ (iii) $$40^o$$$$C$$
  • (i) $$72^o$$$$C$$ (ii) $$94^o$$$$C$$ (iii) $$40^o$$$$C$$
Which one of the following is not a correct match?
  • Tumor Inducing - Ti plasmid
  • DNA probe - Identifies the desired DNA fragment
  • PCR - DNA staining
  • Agarose - Sea weeds
The correct sequence of different steps of polymerase chain reaction is
  • Annealing denaturation extension
  • Denaturation extension annealing
  • Denaturation annealing extension
  • Extension denaturation annealing
In addition to Taq polymerase enzyme which other thermostable DNA polymerases have been isolated to be used in polymerase chain Reaction (PCR)?
  • Pfu polymerase isolated from Pyrococcus furiosus
  • Tli polymerase (vent polymerase) isolated from Thermococcus litoralis
  • Both (a) and (b)
  • None of these
Which of the following is required to perform polymerase chain reaction?
  • Primers, dNTPs and DNA polymerase
  • DNA, Ca$$Cl_2$$ and nuclease
  • $$Mg^{+2}$$, DNABoth (a) and (c)
  • Both (a) and (c)
The figure shows the restriction enzyme cutting sites (R1-R3) in wild type (n) and mutant ($$n^-$$) gene.
If a radioactively labelled probe (that hybridises at a sequence close to R1) is used for detecting the presence of DNA fragments after gel electrophoresis and Southern blotting, which of the following band patterns will your expect?Note: L1 : wild type DNA, L2 : mutant DNA

928065_06bb6c7042aa4539bc319716bec368c2.PNG
The basic procedure involved in the synthesis of recombinant DNA molecule is depicted below. The mistake in the procedure is _______________.
928069_2ec06225024b4424b5efe5a486f16205.png
  • Enzyme polymerase is not included
  • The mammalian DNA is shown double stranded
  • Two different restriction enzymes are used
  • Only one fragment is inserted
The nucleic acid extracted from animal liver is loaded and run on agarose gel. After staining, it shows following pattern:
If the remaining sample is treated with RNAse and loaded in gel what result would you expect? 

928067_658e819f95c0464cbf49e172b3bcf33b.PNG
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