CBSE Class 12 Biology Biotechnology Principles and Processes VBQs

Question. Study the given figure carefully and select the correct statements regarding this. (Image 125)
I. It represents typical agarose gel electrophoresis showing differential migration ofDNAfragments.
II. Lane 1 contains undigestedDNAfragments.
III. Lanes 2 to 4contain digestedDNAfragment.
IV. SmallestDNAbands are present atAposition and largestDNAbands are present atBposition.
(a) I, II and III
(b) I, II and IV
(c) II and III
(d) III and IV
Answer : A

Question. Read the statements about gene gun method.
I. This method is also known as biolistic technique.
II. In this method, cells are bombarded with high velocity microparticles of gold or tungsten coated withDNAin plants.
III. Important crop plants like maize, rice and wheat have now been transformed by this method.
Which of the statements given above are correct?
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
Answer : D

Question. Identify the correct statements.
I. The first recombinantDNAwas constructed by using a piece of DNAfrom plasmid carrying antibioticresistance gene in the bacterium Salmonella typhimurium and linked it to the plasmid of E. coli.
II. When cut by the same restriction enzyme, the resultant DNAfragments have the same kind of sticky ends and these can be joined together usingDNAligases.
III. The presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning.
(a) I, II and III
(b) I and II
(c) Only I
(d) II and III
Answer : A

Question. Read the statements.
I. In the process of recombinantDNAtechnology, after several treatment the purifiedDNAis precipitated by adding chilled acetone.
II. The bacterial/plant, animal cell is broken down by enzymes to releaseDNA, along with RNA, proteins, polysaccharides and lipids.
Choose the correct option for above statements.
(a) I is true, but II is false
(b) I is false, but II is true
(c) I and II are true
(d) I and II are false
Answer : B

Question. Which of the following statements are correct with respect to a bioreactor?
I. It can process small volume of culture.
II. It provides optimum temperature, pH, salt, vitamins and oxygen.
III. Sparged stirred-tank bioreactor is a stirred type reactor in which air is bubbled.
Choose the correct option.
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
Answer : C

Question. Consider the following statements.
I. Bioreactors are vessels of large volumes in which raw materials are biologically converted into specific products.
II. One of the most commonlyused bioreactor is of stirring type.
III. Shake flasks are used for growing andmixing the desiredmaterials on a small scale in the laboratory.
IV. Alarge scale production of desired biotechnological product is done by using ‘bioreactors’.
Which of the statements given above are correct?
(a) I and II
(b) I and III
(c) I, II and III
(d) I, II, III and IV
Answer : D

Question. Which statement is correct?
I. The downstream processing and quality control testing vary from product to product.
II. In bioreactors, raw materials are biologically converted into specific products.
III. Large amount of recombinant protein can be produced by gene cloning.
IV. pBR322 vector was constructed by usingDNA derived from naturally occurring plasmids of E. coli.
(a) I, II and III
(b) Only IV
(c) II, III and IV
(d) All of these
Answer : D

Question. Which statement is incorrect ?
I. Retroviruses have also been disarmed and are now
used to deliver desirable genes into animals cells.
II. Downstream processing is one of the steps ofR-DNA technology.
III. DNAis a negatively charged molecule.
IV. The presence of chromogenic substrate gives blue colour colonies, if the plasmid in the bacteria does not have an insert.
(a) I and II
(b) I, III and IV
(c) All of these
(d) None of these
Answer : D

Question. For selectable marker.
I. It helps to select the host cells which contain the vector and eliminate the non-transformants.
II. Genes encoding resistance to antibiotics like ampicillin, chloramphenicol, tetracycline or kanamycin, are useful selectablemarkers forE.coli.
Which of the statements given above are correct?
(a) Only I
(b) Only II
(c) I and II
(d) None of these
Answer : C

Question. I. DNAbeing a hydrophilic molecule cannot pass through cell membranes.
II. The bacteria should be made competent to accept the DNAmolecule.
The correct option regarding the above statements is
(a) I is true, but II is false
(b) II is true, but I is false
(c) I and II are true
(d) I and II are false
Answer : C

Question. Why foreign DNA cannot pass through cell membrane?
(a) DNA is hydrophobic
(b) DNA is hydrophilic
(c) DNA is rich in proteins
(d) DNA is heavy
Answer : B

Question. The treatment of host cell with divalent cation leads to the
(a) change in permeability of DNA
(b) increased efficiency with which DNA enters the bacterium
(c) decreased efficiency with which DNA enters the bacterium
(d) change in permeability of host
Answer : B

Question. Which vector can clone only a small fragment of DNA?
(a) Bacterial artificial chromosome
(b) Yeast artificial chromosome
(c) Plasmid
(d) Cosmid
Answer : C

Question. The DNA used as a carrier for transferring a fragment of foreign DNA into a suitable host is called 
(a) cloning vector
(b) vehicle DNA
(c) gene carrier
(d) All of these
Answer : D

Question. Which of the following is a plasmid vector?
(a) pBR322
(b) Bam II
(c) SaI I
(d) Eco RI
Answer : A

Question. The method which is used to introduce recombinant DNA into animal cell?
(a) Gene gun method
(b) Changing permeability of host
(c) Biolistic method
(d) Microinjection
Answer : D

Question. Which of the following methods(s) is used to introduce foreign DNA into plant host cells?
(a) Gene gun method
(b) Gel electrophoresis
(c) Elution
(d) Extension
Answer : A

Question. For transformation, microparticles coated with DNA to be bombarded with gene gun are made up of
(a) silver or platinum
(b) platinum or zinc
(c) silicon or platinum
(d) gold or tungsten
Answer : D

Question. DNA transfer with high velocity micro particles is present in
(a) biolistics
(b) hybridisation
(c) tissue culture
(d) vegetative propagation
Answer : A

Question. The different steps involved in the process of recombinant DNA technology are given below randomly? Arrange these in correct order.
I. Extraction of the desired gene product.
II. Amplification of the gene of interest.
III. Isolation of a desiredDNAfragment.
IV. Ligation of theDNAfragment into a vector.
V. Insertion of recombinantDNAinto the host.
Correct order is
(a) I, II, III, IV and V
(b) III, II, IV, V and I
(c) II, IV, V, III and I
(d) I, IV, V, III and II
Answer : B

Question. In bacterial cells, the membrane is digested with the help of enzyme
(a) cellulase
(b) lysozyme
(c) chitinase
(d) lipase
Answer : B

Question. Primers are
(a) small chemically synthesised oligonucleotides of about 10-18 nucleotides that are complementary to the region of template DNA
(b) chemically synthesised oligonucleotides of about 10-18 nucleotides that are not complementary to the region of template DNA
(c) the double-stranded DNA that need to be amplified
(d) specific sequences present on recombinant DNA
Answer : A

Question. The Taq polymerase enzyme is obtained from
(a) Thiobacillus ferroxidans
(b) Bacillus subtilis
(c) Pseudomonas subtilis
(d) Thermus aquaticus
Answer : D

Question. A single PCR amplification cycle involves
(a) denaturation
(b) extension
(c) annealing
(d) All of these
Answer : D

Question. In gel electrophoresis, restriction enzyme digested DNA is loaded in wells near
(a) anode
(b) cathode
(c) centre of gel
(d) any where in the gel
Answer : B

Question. Stirred-tank bioreactors are advantageous over shake flasks because they
(a) provide high temperature and pH
(b) provide better aeration and mixing properties
(c) do not allow the entry of CO2
(d) are easy to operate
Answer : B

Question. Simple stirred-tank bioreactor is given below. Identify
A, B, C, D and E. (Image 100)
Answer : A

Question. The components of a bioreactor are
I. an agitator system.
II. an oxygen delivery system.
III. foam control system.
IV. temperature control system.
V. pH control system.
VI. sampling ports towithdrawcultures periodically.
Choose the correct option.
(a) I, II, III, IV and V
(b) II, IV, V and VI
(c) I, II, III, IV and VI
(d) All of these
Answer : D

Question. 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

Question. Which of the following is not a component of downstream processing?
(a) Separation
(b) Purification
(c) Preservation
(d) Expression
Answer : D

I. Assertion and Reason
In each of the following questions, a statement of Assertion (A) is given followed by corresponding statement of Reason (R). Of the statements, mark the correct answer as
(a) If both A and R are true and R is the correct explanation of A
(b) If both A and R are true, but R is not the correct explanation of A
(c) If A is true, but R is false
(d) If A is false, but R is true

Question. Assertion (A) Biotechnology deals with techniques that use living organism to produce products useful for humans.
Reason (R) It uses only a unicellular organism.
Answer : C

Question. Assertion (A) Maintenance of sterile environment is essential for manufacture of biotechnological products.
Reason (R) This is to enable growth of desired prokaryotic or eukaryotic cells.
Answer : A

Question. Assertion (A) Origin of replication is an essential part of a vector.
Reason (R) Ori is responsible for initiating replication.
Answer : A

Question. Assertion (A) Foreign DNA and vector DNA cut with the help of ligase.
Reason (R) Ligase acts by forming phosphodiester bonds.
Answer : D

Question. Assertion (A) In gel electrophoresis, DNA fragments are separated.
Reason (R) DNA is negatively charged, so it moves towards anode under electric field.
Answer : A

Question. Assertion (A) Restriction endonucleases are also called ‘molecular scissors’.
Reason (R) When fragments generated by restriction endonucleases are mixed, they join together due to their sticky ends.
Answer : B

Question. Assertion (A) All endonucleases cut DNA at specific sites.
Reason (R) Endonucleases were discovered from viruses.
Answer : C

Question. Assertion (A) The tumour inducing plasmid (Ti plasmid) of Agrobacterium tumefaciens acts as a cloning vector in recombinant DNA technology.
Reason (R) The Ti plasmid which is used in the mechanisms of delivering genes to a cell remains pathogenic.
Answer : C

Question. Assertion (A) Use of chitinase enzyme is necessary for isolation of DNA from fungal cells.
Reason (R) Fungal cell wall is made up of chitin and chitinase is able to digest it.
Answer : A

Statement Based Questions

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
Answer : D

Question. Following statements describe the characteristics of the enzyme restriction endonulease. Identify the incorrect statement. NEET 2019
(a) The enzyme binds DNA at specific sites and cuts only one of the two strands
(b) The enzyme cuts the sugar-phosphate backbone at specific sites on each strand
(c) The enzyme recognises a specific palindromic nucleotide sequence in the DNA
(d) The enzyme cuts DNA molecules at identified position within the DNA
Answer : A

Question. Which of the following statement is incorrect?
(a) Nucleic acid is fragmented by nucleases
(b) Construction of recombinant DNA involves cleaning DNA segments with endonuclease and rejoining with ligase
(c) Genetic engineering is making artificial limbs and diagnostic instruments
(d) Ti plasmid transforms cells of plants
Answer : C

Question. Which of the following statement is incorrect?
(a) DNA being a hydrophilic molecule cannot pass through cell membranes
(b) Agrobacterium tumefaciens delivers a piece of DNA known as ‘Z-DNA’ which transforms normal plant cells into tumour cells and directs these tumour cells to produce chemicals against pathogens
(c) Retrovirus, adenovirus, papillomavirus are also now used as cloning vectors in animal because of their ability to transform normal cells into cancerous cell
(d) In genetic engineering, DNA from different sources are cut with the same restriction enzymes so that both DNA fragments have same kind of sticky ends
Answer : B

Question. Consider the following statements and select the correct option.
(a) A soil inhabiting plant bacterium, Agrobacterium tumefaciens, a pathogen of several dicot plants is able to transfer a piece of DNA known as T-DNA
(b) The T-DNA causes tumours
(c) Tumour formation is induced by Ti plasmid
(d) All of the above
Answer : D

Question. Which of the following statement is incorrect?
(a) Each restriction endonuclease recognises a specific palindromic nucleotide sequence
(b) Specific base sequence is known as recognition sequence
(c) Restriction enzymes cannot cut DNA
(d) Restriction enzymes belong to enzymes called nucleases
Answer : C

Question. Which of the following statement is incorrect?
(a) EcoRI cuts the DNA between bases G and A
(b) Making multiple identical copies of any template DNA is called cloning
(c) pBR322 is a natural plasmid
(d) Agrobacterium tumefaciens is a natural genetic engineer
Answer : C

Question. Choose the incorrect statement.
(a) Ori also controls the copy numbers of the linked DNA
(b) If a foreign DNA ligates at the Bam HI site of tetracycline resistance gene in the vector pBR322, the recombinant plasmid loses the tetracycline resistance due to insertion of foreign DNA
(c) Copy number refers to the number of copies of plasmid present in a cell
(d) Copy number of plasmid varies from 50-100 per cell
Answer : D

Question. Which of the statements given is incorrect?
(a) In microinjection method, foreign DNA is directly injected into the nucleus of animal cell by using microneedles
(b) Microinjection method is used in oocytes, eggs and embryo
(c) Electroporation is the formation of temporary pores in the plasma membrane of host cell by using lysozyme or calcium chloride
(d) In chemical mediated gene transfer method, certain chemicals such as Ca phosphate help foreign DNA to enter the host cell
Answer : C

Question. Consider the following statements.
I. RecombinantDNAtechnology popularly known as genetic engineering is a stream of biotechnology which deals with the manipulation of genetic material by manin vitro.
II. pBR322 is the first artificial cloning vector developed in 1977 by Boliver and Rodriquez from E. coli plasmid.
III. Restriction enzymes belong to a class of enzymes called nucleases.
Which of the statements given above are correct?
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
Answer : D

Question. Given below are four statements pertaining to separation of DNA fragments using gel electrophoresis. Identify the incorrect statements.
I. DNAis negatively charged molecule and so it is loaded on gel towards the anode terminal.
II. DNAfragments travel along the surface of the gel whose concentration does not affect movement of DNA.
III. Smaller the size ofDNAfragment larger is the distance it travels through it.
IV. PureDNAcan be visualised directly by exposing UV-radiation.
Select the correct option from the following.
(a) I, III and IV
(b) I, II and III
(c) II, III and IV
(d) I, II and IV
Answer : D

Question. Study the given figure carefully and select the correct statements regarding this. (Image 125)
I. It represents typical agarose gel electrophoresis showing differential migration ofDNAfragments.
II. Lane 1 contains undigestedDNAfragments.
III. Lanes 2 to 4contain digestedDNAfragment.
IV. SmallestDNAbands are present atAposition and largestDNAbands are present atBposition.
(a) I, II and III
(b) I, II and IV
(c) II and III
(d) III and IV
Answer : A

Question. Read the statements about gene gun method.
I. This method is also known as biolistic technique.
II. In this method, cells are bombarded with high velocity microparticles of gold or tungsten coated withDNAin plants.
III. Important crop plants like maize, rice and wheat have now been transformed by this method.
Which of the statements given above are correct?
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
Answer : D

Question. Identify the correct statements.
I. The first recombinantDNAwas constructed by using a piece of DNAfrom plasmid carrying antibioticresistance gene in the bacterium Salmonella typhimurium and linked it to the plasmid of E. coli.
II. When cut by the same restriction enzyme, the resultant DNAfragments have the same kind of sticky ends and these can be joined together usingDNAligases.
III. The presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning.
(a) I, II and III
(b) I and II
(c) Only I
(d) II and III
Answer : A

Question. Read the statements.
I. In the process of recombinantDNAtechnology, after several treatment the purifiedDNAis precipitated by adding chilled acetone.
II. The bacterial/plant, animal cell is broken down by enzymes to releaseDNA, along with RNA, proteins, polysaccharides and lipids.
Choose the correct option for above statements.
(a) I is true, but II is false
(b) I is false, but II is true
(c) I and II are true
(d) I and II are false
Answer : B

Question. Which of the following statements are correct with respect to a bioreactor?
I. It can process small volume of culture.
II. It provides optimum temperature, pH, salt, vitamins and oxygen.
III. Sparged stirred-tank bioreactor is a stirred type reactor in which air is bubbled.
Choose the correct option.
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
Answer : C

Question. Consider the following statements.
I. Bioreactors are vessels of large volumes in which raw materials are biologically converted into specific products.
II. One of the most commonlyused bioreactor is of stirring type.
III. Shake flasks are used for growing andmixing the desiredmaterials on a small scale in the laboratory.
IV. Alarge scale production of desired biotechnological product is done by using ‘bioreactors’.
Which of the statements given above are correct?
(a) I and II
(b) I and III
(c) I, II and III
(d) I, II, III and IV
Answer : D

Question. Which statement is correct?
I. The downstream processing and quality control testing vary from product to product.
II. In bioreactors, raw materials are biologically converted into specific products.
III. Large amount of recombinant protein can be produced by gene cloning.
IV. pBR322 vector was constructed by usingDNA derived from naturally occurring plasmids of E. coli.
(a) I, II and III
(b) Only IV
(c) II, III and IV
(d) All of these
Answer : D

Question. Which statement is incorrect ?
I. Retroviruses have also been disarmed and are now
used to deliver desirable genes into animals cells.
II. Downstream processing is one of the steps ofR-DNA technology.
III. DNAis a negatively charged molecule.
IV. The presence of chromogenic substrate gives blue colour colonies, if the plasmid in the bacteria does not have an insert.
(a) I and II
(b) I, III and IV
(c) All of these
(d) None of these
Answer : D

Question. For selectable marker.
I. It helps to select the host cells which contain the vector and eliminate the non-transformants.
II. Genes encoding resistance to antibiotics like ampicillin, chloramphenicol, tetracycline or kanamycin, are useful selectablemarkers forE.coli.
Which of the statements given above are correct?
(a) Only I
(b) Only II
(c) I and II
(d) None of these
Answer : C

Question. I. DNAbeing a hydrophilic molecule cannot pass through cell membranes.
II. The bacteria should be made competent to accept the DNAmolecule.
The correct option regarding the above statements is
(a) I is true, but II is false
(b) II is true, but I is false
(c) I and II are true
(d) I and II are false
Answer : C

Chapter 1 Reproduction in Organisms
CBSE Class 12 Biology Reproduction in Organisms VBQs
Chapter 10 Microbes in Human Welfare
CBSE Class 12 Biology Microbes in Human Welfare VBQs
Chapter 11 Biotechnology Principles and Processes
CBSE Class 12 Biology Biotechnology Principles and Processes VBQs
Chapter 13 Organisms and Populations
CBSE Class 12 Biology Organisms and Populations VBQs
Chapter 2 Sexual Reproduction In Flowering Plants
CBSE Class 12 Biology Sexual Reproduction In Flowering Plants VBQs
Chapter 5 Principles of Inheritance and Variation
CBSE Class 12 Biology Principles of Inheritance and Variation VBQs
Chapter 6 Molecular Basis of Inheritance
CBSE Class 12 Biology Molecular Basis of Inheritance VBQs
Chapter 8 Human Health and Diseases
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Chapter 9 Strategies for Enhancement in Food Production
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