Genetics MCQs Part IV

1) Human chromosomes have been grouped on the basis of the length and and
centromere into types

a) 5
b) 6
c) 7
d) 10

2) Lyon’s hypothesis is connected with
a) Number of Barr bodies
b) Genetic compatibility
c) Genetic incompatibility
d) Centromere position

3) The genes for the eye colour and size of the wing of Drosophila
are located on the same chromosome. They can be separated by

a) Non-disjunction
b) Crossing over
c) Hybridization
d) Not be separated at any size

4) The sex linked characters are those
a) Which are related to sexual physiology
b) The genes of which are present on the sex chromosome
c) Which appear either in male or in female
d) Which are controlled by sex hormones

5) The chromosomes other than sex chromosomes are called
a) Autosomes
b) Heterosomes
c) Karyosomes
d) None of the above

6) If the crossing over did not occur at the four strand stage in Neurospora,
the ascospores would be arranged in

a) 1-1 position
b) 2-2 position
c) 4-4 position
d) none of these

7) In most of the higher unisexual animals there is one chromosomal
pair which is not identical in two sexes. These are called

a) Non-homologous chromosomes
b) Non-identical chromosomes
c) Non-compatible chromosomes
d) Sex chromosomes

8) A linkage group is defined as
a) All the linked genes of a chromosomal pair
b) Different group of genes present on different chromosomes
c) All the genes located on the same chromosome
d) None of the above

9) A phenomenon which works opposite to the linkage is
a) Independent assortment
b) Crossing over
c) Segregation
d) Mutation

10) The linked characters would always inherit together till they are
a) Delinked due to segregation
b) Masked by dominance
c) Mutated
d) Separated due to crossing over

11) During meiosis, the crossing over which occurs between the homologous
chromosomes is of

a) No genetic significance
b) Importance to bring about recombination of characters
c) Importance because it produce nutrition
d) Importance because it causes reorganization of cytoplasm

12) The mMaize endosperm has 30 chromosomes. How many linkage groups does
it have?

a) 20
b) 10
c) 5
d) 40

13) Linkage in Drosophila was first discovered by
a) Bridges
b) Mendel
c) Bateson and Punnet
d) Morgan

14) An example of complete linkage is
a) Human beings
b) Neurospora
c) Female Drosphila
d) Male Drosophila

15) In human males, some recessive genes express their effect because they have
a) Only autosome
b) Single genome
c) Only two sex chromosomes
d) Only one X-chromosome

16) An exchange of segments between the two non-homologous chromosomes is called
a) Polypoidy
b) Chromosomal aberration
c) Translocation
d) Inversion

17) A mutation is
a) A change in phenotype of an organism caused by some environmental factor
b) An inheritable change in genetic material
c) A temporary change in structure of the nucleus
d) Any one of the following

18) A sudden or spontaneous change in the structure and action of a particular
gene is called

a) Linkage
b) Variation
c) Mutation
d) Allelomorph

19) Gene mutations are those which involve
a) The change in the nature and sequence of base triplets of DNA
b) The change in genome
c) The change in all the genes
d) The disappearance of a certain part of a chromosome

20) What term is applied to the gene mutation where a base is replaced by another

a) Duplication
b) Aneuploidy
c) Euploidy
d) Substitution

21) When a purine is replaced by a pyrimidine in a part of DNA, the mutation
so produced is called

a) Transition
b) Transversion
c) Deletion
d) Reversal

22) Mutations were first induced in Drosophila by the use of
a) X-ray
b) DDT
c) High temperature
d) UV-rays

23) Which of the following is a case of autoallopolyploidy?
a) AA, AA, A
b) AA, AA, AB
c) AA-1
d) 2n-2

24) Which of the following is not an aneuploid?
a) Monoploid
b) 2n-1
c) Trisomic
d) 2n+2

25) The reason for genetic variability in sexually reproducing organisms is
a) Temperature
b) Mutations
c) Certain chemicals
d) Evolution

26) Most of the high yielding varieties of wheat are
a) Imported
b) Monosomic
c) Trisomic
d) Mutants

27) The mutation theory of evolution by Hugo de Vries was based on his studies on
a) Pisum sativum
b) Oenothera lamarckiana
c) Acetabularia
d) Lathyrus odortus

28) Mutagens are
a) The gene which can mutate
b) The organism which show mutation
c) Genes that regulate mutations
d) The agents which cause mutations

29) The frequency of mutation in a species can be increased by the use of
a) X-rays
b) UV-rays
c) Nitrous acid
d) All the above

30) A trisomic individual has
a) One extra chromosome
b) One less chromosome
c) Two extra chromosomes
d) One pair of extra chromosomes

31) X-rays cause mutations by
a) Breaking the spindle
b) Rupturing of nuclear membrane
c) Changing the chromosome morphology
d) Inducing karyokinesis

32) Gene mutations occur in the
a) Chromosome
b) DNA
c) Nucleus
d) RNA

33) The frequency of mutations
a) Can be increased by recombination
b) Varies with the character and the organism
c) Is affected by environmental factors
d) Can be increased by X-rays

34) Kappa particles were discovered by
a) Correns
b) Sonneborn
c) Rhoades
d) Bycott et al

35) Kappa particles are present in
a) Mirabilis jalapa
b) Zea mays
c) Limnaea peregra
d) Paramecium aurelia

36) Number of chromatids per chromosome complex at metaphase is
a) Two both in mitosis and meiosis
b) Two in mitosis and one in meiosis
c) One in mitosis and two in meiosis
d) Two in mitosis and four in meiosis

37) A pollen from a green branch fertilizes an ovum of pale type in Mirabilis
jalapa. What shall be the progeny?

a) Green
b) Variegated
c) Pale
d) All the above

38) Cytoplasmic inheritance is due to
a) Plastids
b) Mitochondria
c) Cytoplasmic particles
d) All the above

39) Cytoplasmic inheritance is also called maternal inheritance because it is
a) Without sexual reproduction
b) Only the female parent takes part in multiplication
c) Mostly provided by the ovum
d) All the above

40) The centromere is part of the
a) Cytoplasmic organelles
b) Ribosome
c) Chromosome
d) Nucleolus

41) Centromere is connected with
a) DNA replication
b) Poleward movement of chromosomes
c) Spindle formation
d) Chromosome segregation

42) The centromere is also called
a) Secondary constriction
b) Chromomere
c) Chromocentre
d) Primary constriction

43) A chromosome with a terminal centromere is
a) Telocentric
b) Acrocentric
c) Polycentric
d) Metacentric

44) The terminal end of the chromosome is the
a) Metamere
b) Centromere
c) Telomere
d) Satellite

45) A nucleosome is made up of
a) Histone wrapped over octameric core of nucleic acid
b) Histone
c) DNA wrapped over an octameric core of histone
d) DNA

46) Polytene chromosomes were seen by
a) Heitz
b) Balbiani
c) Wilson
d) Ruckert

47) In humans, the sex chromosome complement is
a) XX-XY
b) XX-XO
c) ZO-ZZ
d) ZW-ZZ

48) syndrome/mongolism
is due to an

a) Extra sex chromosome
b) Extra 21-st chromosome
c) Extra Y-chromosome
d) Deficient sex chromosome

49) The daughter of a colour blind father and normal mother marries a colour
blind person. Colour blindness in the offspring shall be

a) 50% sons and 50% daughters
b) All sons and daughters
c) All daughters
d) All sons

50) The chromosome number of Down syndrome/ mongolism is
a) 46
b) 47
c) 45
d) 23

51) Genes for colour blindness in humans are carried by the
a) Mother
b) Father
c) Both
d) Abnormal sex

52) The number of autosomes in man is
a) 22 pairs
b) 11 pairs
c) 43 pairs
d) 23 pairs

53) To make a karyotype, chromosomes are photographed during
a) Fertilization
b) Meiosis
c) Mitosis
d) Interphase

54) The correct human chromosome number was first reported by
a) Ford and Hammerton
b) Tijo and Levan
c) Painter and Flemming
d) Morgan and Bridges

55) The correct situation of chromosomes in man is
a) 44 autosomes and 4 sex chromosomes
b) 22 pairs of autosomes and 2 sex-chromosomes
c) 44 autosomes and 1 sex chromosome
d) 22 pairs of autosomes and 3 pairs of sex chromosomes

56) In mongolism, a patient shows:
a) Monosomy
b) Nullisomy
c) Trisomy
d) Barr body

57) Which pair of chromosomes is concerned with Down syndrome?
a) Seventh
b) Eighteenth
c) Twentyfirst
d) Twentythird

58) Whose number of sex chromosomes is normal?
a) Down syndrome
b) Superfemale
c) Klinefelter’s syndrome

d) Turner`s syndrome

59) Down syndrome/mongolism is due to
a) An extra sex chromosome
b) An extra twentyfirst chromosome
c) An extra Y-chromosome
d) a deficient sex chromosome

60) The chromosome number of Down syndrome is
a) 23
b) 45
c) 46
d) 47

61) Down syndrome is due to
a) Linkage
b) Sex-linked inheritance
c) Crossing over
d) Nondisjunction of chromosomes

62) Trisomy of the 21st chromosomes results in
a) Down syndrome
b) Sickle-cell anaemia
c) Turner`s syndrome
d) Klinefelter`s syndrome

63) Which kind of disease is “Down syndrome”?
a) sex-linked
b) viral
c) bacterial
d) autosomal

64) The condition of the sex chromosomes in a male child with Down syndrome will be
a) XO
b) XY
c) XXY
d) XX

65) Which of the following is related with high frequency to Down syndrome?
a) Maternal age
b) Paternal age
c) Both
d) None

66) A person who is trisomic for the 18th chromosome pair has
a) Turner`s syndrome

b) Down syndrome

c) Edward`s syndrome
d) Cri-du-chat syndrome

67) Mongolism, Patau`s syndrome and Edward`s syndrome are due to
a) Allosomal abnormalities
b) Autosomal abnormalities
c) Both A and B
d) None of these

68) The Philadelphia chromosome is reported in patients suffering from
a) Kidney stone
b) Liver disfunction
c) Leukemia
d) Insomia

69) Which autosome in human beings gives rise to the “Philadelphia chromosome”?
a) 18
b) 20
c) 21
d) 22

70) In most animals, the sex of the offspring is established
a) when ovum is formed
b) at the time of fertilization
c) when sex organ appear in the embryo
d) at the birth of the child

71) XY sex chromosomes were discovered by
a) Nettie Stevens
b) Robert Brown
c) M.J.D. White
d) Gregor Johann Mendel

72) The sex-determining chromosomes are called
a) autosomes
b) heterosomes
c) centrosomes
d) spherosomes

73) A girl receives her X-chromosomes from
a) her father only
b) her mother only
c) both father and mother
d) the extranuclear DNA from her mother`s egg

74) A boy receives his X-chromosome from
a) his mother only
b) his father only
c) both his father and mother
d) either his mother or father

75) The males of grasshoppers and bugs possess two sets of autosomes and
a) X and Y chromosomes
b) Only X chromosomes
c) Only Y chromosomes
d) Neither X nor Y chromosome

76) Which chromosome set is found in the male grasshopper?
a) XY
b) X
c) YY
d) XX

77) The sex determination pattern in the honeybee is called
a) female haploidy
b) gametic diploidy
c) gametogony
d) haplodiploidy

78) The larva of Bonellia settling near the proboscis of the adult female develops into a male due to
a) substances secreted by the proboscis
b) carbon dioxide in the environment
c) oxygen in the environment
d) electrolytes in water

79) The chromosomal complement in a human zygote designed to develop into a female is
a) 44 + XY
b) 22A + X
c) 23 pairs of autosomes
d) 44 + XX

80) In man, sex determination depends upon the chromosomes present in the
a) male and female gametes
b) male gametes
c) female gametes
d) none of these

81) a human offspring will be female if the 23rd pair of chromosomes in the zygote is
a) XYY
b) YY
c) XY
d) XX

82) When released from the ovary, the human egg contains
a) one Y-chromosome
b) two Y-chromosomes
c) one X-chromosome
d) XY chromosomes

83) The sex of a child depends upon the
a) nature of the sperm
b) nature of the egg
c) health of the father
d) age of the mother

84) A family has five girls and no sons. The probability of the sixth child being a son will be
a) 20%
b) 75%
c) 50%
d) 100%

85) In humans, the sex chromosome complement is
a) XX-XY
b) ZO-ZZ
c) XX-XO
d) ZZ-ZW

86) The unfertilized egg of a human contains
a) one Y chromosome
b) X and Y chromosomes
c) XX chromosomes
d) One X chromosome

87) The number of autosomes in the normal human sperm is
a) one
b) two
c) 46
d) 22

88) The average ratio of men and women in the human population is
a) 1:1
b) 1:2
c) 3:4
d) 3:5

89) A male child is conceived when a sperm with
a) an X-chromosome fertilises the ovum
b) a Y-chromosome fertilises the ovum
c) Both X and Y fertilises the ovum
d) None of these

90) Supermale and superfemale type of determination of sex in Drosophila is based on
a) Gene balance
b) Oxygen balance
c) Biodiversity
d) Uniformity

91) Gynandromorphs are
a) half male and half female
b) male with female character
c) female with male character
d) none of these

92) In human beings 45 chromosomes (44 + XO) causes
a) Edward`s syndrome
b) Turner`s syndrome
c) Klinefelter`s syndrome
d) Down syndrome

93) The number of X chromosomes in Turner`s syndrome is
a) 3
b) 2
c) 1
d) 0

94) Turner`s syndrome in humans is caused by
a) polyploidy
b) autosomal aneuploidy
c) sex chromosomal aneuploidy
d) point mutation

95) A webbed neck is a characteristic of
a) XXX
b) XXY
c) YY
d) XO

96) Klinefelters`s syndrome has
a) 66 + XXY
b) 45 + XY
c) 44 + XXY
d) 44 + XO

97) XXY chromosome complement is found in
a) Down`s syndrome
b) Superfemale
c) Turner`s syndrome
d) Klinefelter`s syndrome

98) An abnormal male phenotype involving an extra X chromosome (XXY) is a case of
a) Down`s syndrome
b) Intersex
c) Klinefelter`s syndrome
d) Edward`s syndrome

99) In which disease does man have an extra X chromosomes?
a) Klinefelter`s syndrome
b) Down`s syndrome
c) Turner`s syndrome
d) Bleeder`s disease

100) Which of the following has the character of Klinefelter`s syndrome?
a) XXY
b) XX
c) XY
d) XO


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