CBSE Class 12 Biology Biotechnology Principles and Processes MCQs Set 03

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

Answer : D

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) and (iv)
(b) (i) only
(c) (i) and (iii)
(d) (ii) and (iv)

Answer : D

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

Answer : C

Question. The DNA fragments produced by the use of restriction endonucleases can be separated by
(a) polymerase chain reaction
(b) gel electrophoresis
(c) density gradient centrifugation
(d) any of the above.

Answer : B

Question. Elution means
(a) making the DNA bands visible under UV radiation
(b) separation of DNA fragments on agarose gel
(c) isolating alien DNA from the choice organism
(d) cutting and extraction of DNA bands from the agarose gel.

Answer : D

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

Answer : A

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)

Answer : D

Question. Restriction endonucleases are
(a) used for in vitro DNA synthesis
(b) synthesised by bacteria as part of their defence mechanism
(c) present in mammalian cells for degradation of DNA when the cell dies
(d) used in genetic engineering for ligating two DNA molecules.

Answer : B

Question. A gene whose expression helps to identify transformed cell is known as
(a) vector
(b) plasmid
(c) structural gene
(d) selectable marker.

Answer : D

Question. Genes of interest can be selected from a genomic library by using
(a) Restriction enzymes
(b) Cloning vectors
(c) DNA probes
(d) Gene targets

Answer : A

Question. In an experiment, recombinant DNA bearing ampicillin-resistance gene is transferred into E.coli cells. The host cells are then cultured on a medium containing ampicillin. The result will be
(a) both transformants and non-transformants cannot survive.
(b) both transformants and non-transformants can survive.
(c) transformants only and not the non-transformants can survive.
(d) transformants cannot survive, but non-transformants can not.

Answer : C

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

Answer : C

Question. Genes of interest can be selected from a genomic library by using
(a) Restriction enzymes
(b) Cloning vectors
(c) DNA probes
(d) Gene targets

Answer : A

Question. A single strand of nucleic acid tagged with a radioactive molecule is called
(a) vector
(b) selectable marker
(c) plasmid
(d) probe.

Answer : D

Question. The correct order of steps in Polymerase Chain Reaction (PCR) is
(a) extension, denaturation, annealing
(b) annealing, extension, denaturation
(c) denaturation, extension, annealing
(d) denaturation, annealing, extension.

Answer : D

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.

Answer : D

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

Answer : D

Question. Which one of the following techniques made it possible to genetically engineer living organisms?
(a) Recombinant DNA techniques
(b) X-ray diffraction
(c) Heavier isotope labelling
(d) Hybridisation

Answer : A

Question. Which of the following statement is not correct about cloning vector ?
(a) ‘Ori’ is a sequence responsible for controlling the copy number of the linked DNA.
(b) Selectable marker selectively permitting the growth of the non-transformants.
(c) In order to link the alien DNA, the vector needs to have single recognition site for the commonly used restriction enzymes.
(d) The ligation of alien DNA is carried out at a restriction site present in one of the two antibiotic resistance genes.

Answer : B

Question. Identify the wrong statement with regard to restriction enzymes.
(a) Each restriction enzyme functions by inspecting the length of a DNA sequence.
(b) They cut the strand of DNA at palindromic sites.
(c) They are useful in genetic engineering.
(d) Sticky ends can be joined by using DNA ligases.

Answer : D

Question . A recombinant DNA molecule can be produced in the absence of the following:
(a) Restriction endonuclease
(b) DNA ligase
(c) DNA fragments
(d) E. coli.

Answer : D

Question. Recombinant DNA is achieved by cleaving the pro-DNAs by
(a) ligase
(b) restriction endonuclease
(c) primase
(d) exonucleases.

Answer : B

Question. In genetic fingerprinting, the ‘probe’ refers to ––––––
(a) a radioactively labelled single stranded DNA molecule.
(b) a radioactively labelled single stranded RNA molecule.
(c) a radioactively labelled double stranded RNA molecule.
(d) a radioactively labelled double stranded DNA molecule.

Answer : A

Question. Which of the following restriction enzymes produces blunt ends?
(a) SalI
(b) EcoRV
(c) XhoI
(d) HindIII

Answer : B

Question. The sequence that controls the copy number of the linked DNA in the vector, is termed
(a) selectable marker
(b) Ori site
(c) palindromic sequence
(d) recognition site.

Answer : B

Question. Given below are four statements pertaining to separation of DNA fragments using gel electrophoresis. Identify the incorrect statements.
(i) DNA is negatively charged molecule and so it is loaded on gel towards the anode terminal.
(ii) DNA fragments travel along the surface of the gel whose concentration does not affect movement of DNA.
(iii) Smaller the size of DNA fragment larger is the distance it travels through it.
(iv) Pure DNA can be visualized directly by exposing UV radiation.
Choose correct answer from the options given below.
(a) (i), (iii) and (iv)
(b) (i), (ii) and (iii)
(c) (ii), (iii) and (iv)
(d) (i), (ii) and (iv)

Answer : D

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

Answer : D

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

Answer : C

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

Answer : B

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

Answer : A

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

Answer : C

Question. Which of the following steps are catalysed by Taq 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

Answer : C