Genetics MCQs Part VII

1) Starting and stopping codons are
a) AUG and UGA
b) GUA and AAA
c) UCA and UAA
d) GUC and AUG

2) Polyribosomes are formed when ribosomes are connected by
a) rRNA
b) mRNA
c) tRNA
d) All the above

3) During elongation of a polypeptide chain, sigma factor is
a) Functionless
b) Retained for specific function
c) Released for re-used
d) Required during closing of chain

4) The best method to determine paternity is
a) Protein analysis
b) Chromosome counting
c) Gene counting
d) DNA finger printing

5) Characters are transferred from parents to progeny through:
a) DNA
b) Protein
c) RNA
d) Phospholipid

6) To check paternity, the most accurate way of testing is
a) Sex of persons
b) DNA fingerprinting
c) Chromosome testing
d) All the above

7) Cell division requires that the genetic material be able to
a) store information
b) be replicated
c) undergo rate mutations
d) all of these are correct

8) The transforming principle of pneumococcus
as found out by Avery, MacLeod and McCarty was:

a) Single stranded DNA
b) RNA
c) Double stranded DNA
d) Proteins

9) Which of the following pair is correctly matched?
a) Frederick Griffith - discovered the Phenomenon of transformation
b) Linus Pauling - isolated DNA for the first time
c) Francis Crick - proposed one gene-one polypeptide hypothesis
d) George Beadle - Proposed the concept of inborn errors

10) Who proved that DNA is the basic genetic material?
a) Griffith
b) Boveri and Sutton
c) Hershey and Chase
d) Watson

11) Hershey and Chase demonstrated that DNA and not protein is the genetic
material with the help of the radioactive isotopes

a) Nitrogen – 15 and Carbon – 14
b) Sulphur – 35 and Phosphorus – 32
c) Iodine – 131 and Calcium – 45
d) Iron – 59 and Nitrogen – 15

12) Blender experiments of Hershey and Chase demonstrated that DNA is genetic
material in

a) TMV
b) E coli
d) Diplococcus pneumoniae

13) The dye involved in the Feuglen reaction to stain DNA is
a) Janus Green B
b) Neutral Red
c) Basic Fuchsin
d) Haematoxylin

14) Which one of the following is not present in nucleic acid?
a) Lipids
b) Ribose
c) Phosphate
d) Haematoxylin

15) The nitrogenous bases in DNA are

16) A nucleoside differs from a nucleotide in not having a
a) Phosphate
b) Sugar
c) Nitrogen base
d) Phosphate and sugar

17) The process in which the DNA of a bacterial cells is transferred into another
bacterial cell is through

a) Transduction
b) Transformation
c) Conjugation
d) Reproduction

18) Which of the following scientists demonstrated that in DNA A=T and G=C?
a) Griffith
b) Chargaff
c) Meselson and Stahl
d) Hershey and Chase

19) If 30% of an DNA is thymine, then
a) 70% is purine
b) 20% is guanine
c) 30% is adenine
d) both (b) and (c) are correct

20) Semi conservation in DNA replication was first demonstrated by
a) Taylor
b) Watson and Crick
c) Meselson and Stahl
d) Khorana

21) Taylor demonstrated that chromosome replication is semi-conservative

a) Vicia faba
b) Mouse liver cell
c) Pea nut
d) HeLa cell

22) Experiments using
(heavy nitrogen to confirm the semiconservative replication of DNA were carried out by

a) Meselson and Stahl
b) Hershey and Chase
c) Beadle and Tatum
d) Watson and Crick

23) If you grew bacteria in heavy nitrogen and then switched them
to light nitrogen, how many generations after switching would
some have light/light DNA?

a) never, because replication is semi conservative
b) the first generation
c) the second generation
d) only the third generation

24) Experimental material for the study of DNA replication has been

25) DNA having labeled thymidine is allowed to replicate in a medium having non-radioactive
thymidine. After three duplications, the DNA molecules having labelled thymidine
shall be

a) One molecule
b) Two molecules
c) Four molecules
d) Eight molecules

26) Escherichia coli with completely radioactive DNA was allowed to replicate
in a non-radioactive medium for two generations. Percentage of bacteria with
radioactive DNA is

a) 12.5
b) 25
c) 50.0
d) 100

27) DNA replication is
a) continuous and conservative
b) semiconservative and semidiscontinuous
c) conservative and semidiscontinous
d) semiconservative and discontinuous

28) DNA replication in eukaryotes commences
a) From one end of chromosome to other
b) From both ends of a chromosome simultaneously
c) From the centromere to either end
d) At several sites along the DNA of a chromosome simultaneously

29) Replication of DNA does not require
a) DNA polymerase
b) RNA polymerase
c) Ligase
d) Dinase

30) During DNA replication, the sequence specificity of bases in the newly
synthesized strand is due to

a) DNA-polymerase I
b) DNA-polymerase II
c) Restriction endonuclease
d) The template strand

31) Eukaryotes differ from prokaryotes in the mechanism of DNA replication due to
a) DNA primers instead of RNA primers
b) Different enzymes for lagging and leading strands
c) Unidirectional rather than bidirectional
d) Discontinous rather than semidiscontinuous replication

32) The protein helping in the opening of the DNA double helix in front of the replication fork

a) DNA gyrase
b) DNA ligase
c) DNA topoisomerase
d) DNA polymerase I

33) DNA replication requires
a) DNA ligase
b) DNA polymerase
c) RNA polymerase and translocase
d) DNA ligase and DNA polymerase

34) DNA polymerase helps in
a) Joining the monomers of DNA
b) Proof reading of DNA
c) Renaturation of DNA
d) Splitting of two DNA strands

35) The enzyme which can cut molecules of DNA into segments is known as
a) DNA polymerase
b) DNA ligase
c) Restriction enzyme
d) DNA gyrase

36) Ligase is an enzyme required for
a) Breaking of DNA
b) Joining DNA bits
c) Proof reading
d) Renaturation of DNA

37) Which of the following enzyme makes short RNA chains using a DNA template?
a) DNA polymerase I
b) DNA helicase
c) Primase
d) DNA grase

38) The enzyme which relaxes supercoiled DNA is
a) Topoisomerase I
b) DNA gyrase
c) DNA polymerase III
d) Primase

39) During DNA replication, the sequence
would produce which of the following complementary structures?


40) The one gene-one enzyme hypothesis was proposed by
a) Sutton and Boveri
b) Watson and crick
c) Beadle and Tatum
d) Jacob and Monod

41) DNA is
a) right-handed coiling and parallel
b) right-handed coiling and anti-parallel
c) left-handed coiling and anti-parallel
d) left-handed coiling and parallel

42) Z-DNA was discovered by
a) Watson and Crick
b) Wang and Rich
c) Meselson and Stahl
d) Franklin and Wilkins

43) Pyrimidines of RNA are represented by
a) Thymine and Cytosine
b) Adenine and Cytosine
c) Uracil and Guanine
d) Cytosine and Uracil

44) Who established that RNA is genetic material?
a) Nirenberg and Holley
b) Lederberg
c) Fraenkel conrat
d) Griffith

45) Which purine base is found in RNA?
a) Uracil
b) Guanine
c) Thymine
d) Cytosine

46) RNA is a
a) Polynucleoside
b) Polynucleotide
c) Carbohydrate
d) Proteins

47) A ribosome is
a) Ribose + Phosphate +Base
b) Ribose + Base
c) Ribose + Phosphate
d) Base + phosphate

48) RNA is not found in
a) Cytoplasm
b) Nucleus
c) Cell sap
d) Ribosomes and cytoplasm

49) RNA is absent in the
a) Plasmalemma
b) Ribosome
c) Chromosomes
d) Cytoplasm

50) One of the following is a nucleotide found only in RNA:
a) Cytosine-pentose sugar-phosphate
b) Guanine-pentose sugar-phosphate
c) Uracil-pentose sugar-phosphate
d) Thymine-pentose sugar-phosphate

51) If the nucleolus of the cell is destroyed, which of these in the cell
will not be formed?

a) Lysosomes
b) Ribosomes
c) Microtubules
d) Mitochondria

52) Transcription involves:
a) Protein synthesis over ribosomes
b) Removal of worn out organelles by lysosomes
c) Synthesis of DNA over DNA
d) Synthesis of RNA over DNA

53) If the sequence of bases in DNA is ATTCGATG, then the sequence of the
bases in its transcript will be


54) The DNA chain acting as a template for RNA synthesis has the following
order of bases, AGCTTCGA. What will be the order of bases in m-RNA?


55) The m-RNA is formed
a) By free ribosomes
b) From ribosomes on the ER
c) In the nucleus
d) From DNA in the nucleus

56) The type of RNA specifically responsible for directing the proper sequence
of amino acids in protein synthesis is

a) m RNA
b) r-RNA
c) t-RNA
d) none of the above

57) Nuclear DNA sends information for protein synthesis through
a) t-RNA
b) m-RNA
c) r-RNA
d) all the above

58) The term triplet codon refers to a sequence of three bases on
a) m-RNA
b) r-RNA
c) t-RNA
d) all the above

59) mRNA is made up of
a) Ribonucleosides
b) ribonucleotides
c) Deoxyribonucleosides
d) Deoxyribonucleosides

60) The maximum formation of m-RNA occurs in the
a) Cytoplasm
b) Nucleoplasm
c) Ribosome
d) Centrosome

61) RNA plays an important role in
a) Cell division
b) Synthesis of protein
c) Digestion of protein
d) Synthesis of carbohydrate

62) Protein biosynthesis requires all the following except:
a) Peptidyl transferase
b) Ribosomal RNA
c) Messenger RNA
d) Primer protein

63) The codon for anticodon 3’UUA 5′ is

64) Adenine of transfer RNA will pair with
a) Thymine
b) Cytosine
c) Uracil
d) Guanine

65) Which site of a t-RNA molecule hydrogen bonds to a m-RNA molecule?
a) Codon
b) Anticodon

66) The codon of m-RNA and the anticodon of t-RNA is made of
a) A set of two nitrogen bases
b) A set of three and two respectively
c) A set of three out of U, A, C and G
d) Three and one nitrogen bases respectively

67) Which of the following is the smallest RNA?
a) m-RNA
b) r-RNA
c) t-RNA
d) Chromosomal RNA

68) The function of t-RNA is
a) Production of microsomes
b) Selection of amino acids
c) Production of ribosomes
d) Production of m-RNA

69) If the codon of a m-RNA is AUG what should be its anticodon on t-RNA?
a) UAC
b) TAC
c) CUA
d) AUG

70) The most abundant RNA in a cell is
a) r-RNA
b) m-RNA
c) t-RNA
d) Primary RNA

71) Ribosomal RNA is synthesised in the
a) Nucleosome
b) Nucleolus
c) Ribosome
d) Lysosome

72) The most stable RNA in the cell is
a) r-RNA
b) m-RNA
c) t-RNA
d) both a and c

73) Double stranded RNA is present in
a) Bacteria
b) Chloroplasts
c) Reoviruses
d) Mitochondria

74) The pyrimidine base present in RNA in place of the thymine of DNA is
a) Uracil
b) Adenine
c) Guanine
d) Cytosine

75) RNA contains:
a) Glucose
b) Hexose
c) Ribose
d) Fructose

76) Which is present in RNA but not in DNA?
a) Adenine
b) Guanine
c) Thymine
d) Uracil

77) The genetic code was discovered by
a) Holley and Ochoa
b) Holley, Nirenberg and Khorana
c) Nirenberg and Matthaei
d) Watson and Crick

78) The diamond code was proposed by
a) Nirenberg
b) George Gamow
c) Har Govind Khorana
d) J.H. Matthaei

79) The first deciphering of the genetic code through trinucleotide synthesis
was performed by

a) Ochoa
b) Beadle and Tatum
c) Watson and Crick
d) Nirenberg

80) A triplet codon means
a) The presence of only three bases in mRNA
b) A sequence of three nitrogen bases in rRNA
c) A sequence of three nitrogen bases in mRNA
d) A sequence of three nitrogen bases in tRNA

81) The triplet codes for several amino acids were experimentally
determined by

a) Beadle and Tatum
b) Nirenberg and his associates
c) Lederberg and Tatum
d) Watson and Crick

82) The arrangement of three bases in the genetic code signifies
a) A protein
b) An amino acid
c) A plasmid
d) A nucleic acid

83) The first codon discovered by Nirenberg and Matthaei was
a) UUU
b) AAA
c) GGG
d) CCC

84) The genetic code consists of
a) Cytosine and guanine
b) Uracil and cytosine
c) Guanine and adenine
d) All the above

85) In the process of altering the code in the DNA sequence, the
message is reversed. This is called

a) deletion
b) inversion
c) translocation
d) none of these

86) In the coding dictionary, there are 64 codons as
a) The genetic code is triplet
b) 64 amino acids are to be coded
c) 64 types of tRNA are present
d) there are 44 non-sense codons and 20 sense codons

87) A degeneracy in genetic code was found by
a) Khorana
b) Ochoa
c) Bernfield and Nirenberg
d) McClintock

88) Genetic code is said to be degenerate because
a) codons degenerate very quickly
b) one amino acid is coded for by more than one codon
c) one codon codes for more than one amino acid
d) none of the above

89) Because most of the amino acids are represented by more than
one codon, the genetic code is

a) Wobbling
b) Overlapping
c) Generate
d) Degenerate

90) The initiation codon in eukaryotes is
a) UAC
b) AGU
c) GAU
d) AUG

91) The initiation of the polypeptide chain is through
a) Lysine
b) Leucine
c) Glycine
d) Methionine

92) The codons causing chain termination are

93) The termination signal for protein synthesis comes from
a) UAA
b) AUU
c) GUG
d) CTT

94) The single-stranded DNA phage
contains approximately 5400 nucleotides. If an average protein contains 200 amino acids, how many different proteins could this phage DNA

a) 100
b) 90
c) 9
d) 10

95) Non-sense codon takes part in
a) The formation of unspecified amino acids
b) Terminating the message of gene controlled protein synthesis
c) Releasing tRNA from the polypeptide chain
d) Conversion of sense DNA into non-sense DNA

96) The nuclease enzyme is capable of
b) Breaking phosphodiester bonds
c) Breaking disulphide bonds
d) Removing the terminal nucleotide

97) An anticodon of tRNA can recognize more than one codon of
mRNA. This is the

a) Wobble hypothesis
b) Template hypothesis
c) Gene flow hypothesis
d) Richmond and Lang effect

98) The wobble hypothesis establishes
a) Economy in tRNA molecules
b) Peptide chain formation
c) Termination of the peptide chain
d) Initiation of the peptide chain

99) Protein synthesis occurs in the
a) Mitochondria
b) Ribosomes
c) Lysosomes
d) Chloroplasts

100) Protein hydrolyses into
a) Amino acids
b) Nucleic acids
c) Nucleotides
d) Nucleosides


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