MCQ on Animal Biotechnology – B

DNA replication and transcription

Prepared by: Dr Sajad Ahmad Beigh
M.V.Sc, Division of Animal Biotechnology, SKUAST-K

  1. Which of the following is not related to okazaki fragments
    (a) Lagging strand
    (b) DNA polymerase III
    (c) DNA ligase
    (d) DNA gyrase
  2. Which of the following is true about origin of replication
    (a) It is a trans-acting site
    (b) It is called autonomously repeated sequence in yeast
    (c) It is GC-rich stretch
    (d) OriC in prokaryotes is about 500bp long
  3. Circular DNA replication can be explained by which model
    (a) Theta replication model
    (b) Sigma replication model
    (c) Both
    (d) None
  4. Which of the following is not a nuclease
    (a) dnaB
    (b) HindIII
    (c) Topoisomerase
    (d) Maturase
  5. Which is the only prokaryotic DNA polymerase having 5′-3′ exonuclease activity
    (a) DNA polymerase I
    (b) DNA polymerase II
    (c) DNA polymerase III
    (d) DNA polymerase IV
  6. Which class of antibiotics inhibit the activity of DNA gyrase
    (a) Third generation cephalosporins
    (b) Aminoglycosides
    (c) Sulphonomides
    (d) Fluoroquinolones
  7. Which of the following is true about aphidicolin
    (a) It is a mutagen
    (b) Tetracyclic diterpenoid
    (c) Inhibitor of mammalian nuclear DNA polymerase
    (d) Both b and c
  8. In eukaryotes RNA primers are removed by
    (a) DNA polymerase
    (b) RNase E
    (c) RNase H
    (d) Flap endonuclease
  9. DNA replication in eukaryotes is
    (a) Semi-consevative
    (b) Semi-discontinuous
    (c) Dispersive
    (d) Both a and b
  10. Which of the following is true about replication
    (a) The velocity of nucleotide addition per fork is higher in prokaryotes than eukaryotes
    (b) DNA polymerase V is error prone polymerase
    (c) DNA polymerase III is having high processivity
    (d) All of the following
  11. Which of the following eukaryotic DNA polymerases is correctly matched
    (a) DNA polymerase α———– repair mechanism
    (b) DNA polymerase β——— leading strand replication
    (c) DNA polymerase γ———– mitochondrial DNA replication
    (d) DNA polymerase δ———- lagging strand replication
  12. Which of the following polymerase is used for high fidelity DNA synthesis
    (a) Taq polymerase
    (b) Pfu polymerase
    (c) Polymerase V
    (d) Both a and b
  13. Which of the following is direct mutation repair in DNA
    (a) Pyrimidine dimers
    (b) O6-methylguanosine
    (c) Both
    (d) None
  14. Which of the following is not correct about SOS response in E. Coli
    (a) Occurs due to severe DNA damage
    (b) RecA protein participates in it
    (c) It is responsible for error prone replication
    (d) Occurs due to high lactose in media
  15. Which among the following is cofactor for RNA polymerase
    (a) Zn2+
    (b) Mg2 +
    (c) Fe2+
    (d) Both a and b
  16. Which of the following is not true about RNA polymerase
    (a) σ factor helps in promotor recognition
    (b) β and β’ occur in catalytic core
    (c) working direction is 5′-3′
    (d) it requires primer for activity
  17. Which of the following sigma factor is correctly matched with its function
    (a) σ54————-oxidative and osmotic response
    (b) σ32———– nitrogen assimilation
    (c) σ28———— flagellar synthesis
    (d) σ38————- heat shock response
  18. Which among the following is adenosine analog that blocks RNA synthesis
    (a) Cordycepin
    (b) Ricin
    (c) Rifampicin
    (d) 5-bromouracil
  19. Which of the following is not true about Rho protein
    (a) It is an ATP- dependent hexamer
    (b) It binds to RNA at rut sequence
    (c) It disrupts nascent RNA-DNA complex
    (d) It is an endonuclease
  20. Which eukaryotic RNA polymerase is resistant to ɑ-amanitin
    (a) RNA pol. I
    (b) RNA pol. II
    (c) RNA pol. III
    (d) All of the following
  21. Which among the following is false
    (a) miRNA is synthesized by RNA pol. II
    (b) mitochondrial RNA polymerase is encoded by nuclear genes
    (c) chloroplast RNA polymerase is encoded by both nuclear and chloroplast genes
    (d) the DNA strand from which transcription occurs is called (+) strand
  22. Which reaction is used for removal of introns
    (a) Methylation
    (b) Acetylation
    (c) Trans-esterification
    (d) O-glycosylation
  23. Which of the following is true about cajal bodies
    (a) located within nucleus
    (b) Centres of post-transcriptional modification of SnRNAs and snRNPs
    (c) Migrate between nucleoplasm and cytoplasm
    (d) Both a and b
  24. Regulated alternate splicing is used for sex determination in
    (a) C. elegans
    (b) Drosophila spp.
    (c) Trypanosoma spp.
    (d) Babesia spp.
  25. In trans-splicing the removed introns form which type of structure
    (a) T-shaped
    (b) X-shaped
    (c) Y-shaped
    (d) I-shaped
  26. Trans-splicing has been reported in
    (a) Babesia
    (b) Trypanosoma
    (c) Thieleria
    (d) Anaplasma
  27. Which of the following does not occur in 5′-3′ direction
    (a) RNA editing
    (b) m-RNA degradation
    (c) m-RNA surveillance
    (d) both a and b
  28. which of the following is true about Group 1 introns
    (a) found in transcripts of pre-rRNA genes and some organelle genes
    (b) act as ribozymes
    (c) found in both prokaryotes and eukaryotes
    (d) All of the following
  29. Which among the following is false
    (a) Group 1 introns were discovered first of all in Tetrahymena thermophile
    (b) Group 2 introns are found in transcripts of some organelle genes
    (c) Both group1 and 2 introns act as ribozymes
    (d) They require ATP for splicing
  30. Which of the following is not true about riboswitches
    (a) Elements within mRNA that bind to ligands and regulate mRNA expression
    (b) Cis-acting regulatory elements
    (c) Most often located at 5′ UTR
    (d) Tri-domanic structure
  31. Which of the following is dsRNA
    (a) tRNA
    (b) miRNA
    (c) hnRNA
    (d) all of the above
  32. The endonucleases found in RNA-induced silencing complex(RISC) are called
    (a) Aconitase
    (b) Dicer
    (c) Drosha
    (d) Argonaute
  33. Which of the following is a component of microprocessor complex during miRNA synthesis
    (a) Drosha
    (b) Pasha
    (c) DGCR8
    (d) All of the following
  34. Pre-miRNA derived from introns are called
    (a) Pasha
    (b) Mitons
    (c) Specialized introns
    (d) Mirtrons
  35. Which of the following is an initiator codon
    (a) AUG
    (b) GUG
    (c) UUG
    (d) All of the above
  36. Which of the following was first codon to be discovered
    (a) UUU
    (b) AUG
    (c) GUG
    (d) AAA
  37. The secondary structure of tRNA looks like______ while its 3-D structure looks like____
    (a) Clover leaf, inverted-L
    (b) L-shaped, clover leaf
    (c) X-shaped, Y-shaped
    (d) None of the above
  38. Which of the following rRNA act as peptidyl transferases in prokaryotes and eukaryotes respectively
    (a) 16S,18S
    (b) 16S,28S
    (c) 23,5S
    (d) 23S,28S
  39. Which of the following is not true about shine-dalgarno sequence
    (a) Polypurine sequence located upstream of initiator codon
    (b) Complementary to 3′ end of 16S rRNA
    (c) Helps in attachment of smaller subunit with mRNA
    (d) Conserved sequence found in both eukaryotes and prokaryotes
  40. Selection of initiator codon in eukaryotes is facilitated by surrounding nucleotides called
    (a) preceding sequence
    (b) Kozak sequence
    (c) Trailer sequence
    (d) shine-dalgarno sequence
  41. Which enzyme is used in chemical proof reading of proteins
    (a) Peptidyl transferase
    (b) Aminoacyl-tRNA synthetase
    (c) Pronase
    (d) Both a and b
  42. Cap snatching mechanism of host mRNA is associated with which virus
    (a) Lentivirus
    (b) Retroviruse
    (c) Myxoviruse
    (d) Influenza virus
  43. Which of the following binds to 50S subunit and inhibits protein synthesis
    (a) Streptomycin
    (b) Chloramphenicol
    (c) Tetracycline
    (d) Cyclohexidine
  44. Diptheria toxin inhibits protein synthesis in eukaryotes by inactivating
    (a) 60S subunit
    (b) 40S subunit
    (c) eEF2
    (d) eEF1
  45. In protein splicing the removed residues are called
    (a) Inteins
    (b) Exteins
    (c) Integreins
    (d) Zymogen
  46. Protein synthesis on ribosomes occurs from
    (a) N-terminal to C-terminal
    (b) C-terminal to N-terminal
    (c) Both
    (d) None
  47. Which of the following is used for detection of post-transcriptional modification of proteins
    (a) Western bloating
    (b) Northern bloating
    (c) Southern bloating
    (d) Eastern bloating
  48. IPTG is an
    (a) Inducer
    (b) Repressor
    (c) Both
    (d) None
  49. Which of the following is not true about transposons
    (a) Frequency of movement varies from 10-7to 10-2
    (b) Movement is independent of donor and recipient site
    (c) Sometimes called selfish DNA
    (d) They were first of all found in drosophila
  50. Which of the following uses replicative transposition to evade host immune system
    (a) Trypanosoma brucei
    (b) Trypanosoma cruzi
    (c) Trypanosoma evansi
    (d) Babesia bovis
  51. Ty elements of yeast are examples of
    (a) Class I transposons
    (b) Class II transposons
    (c) retroposons
    (d) retrotransposons
  52. which of the following is not true about retrotransposons
    (a) retrovirus like elements
    (b) have gag and pol genes but lack env genes
    (c) Ty elements and copia elements are retrotransposons
    (d) Found in prokaryotes only

1.(d) 2.(b) 3.(c) 4.(a) 5.(a) 6.(d) 7.(d) 8.(c) 9.(d) 10.(d) 11.(c) 12.(b) 13.(c) 14.(d) 15.(d) 16.(d) 17.(c) 18.(a) 19.(d) 20.(a) 21.(d ) 22.(c ) 23.(d ) 24.(b ) 25.( c) 26.(b ) 27.(d ) 28.(d ) 29.(d ) 30.(d ) 31.(b ) 32.(d ) 33.(d ) 34.(d ) 35.(d) 36.(a) 37.(a) 38.(d) 39.(d) 40.(b) 41.(b) 42.(d ) 43.( b) 44.(c ) 45.(a) 46.(a) 47.(d) 48.(a) 49.(d) 50.(a) 51.(d) 52.(d)

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