Genetics MCQs Part II

1) In angiosperms how many microspore mother cells are required to produce 100 pollen grains?
a) 25
b) 50
c) 75
d) 100

2) The centromere is required for the
a) Poleward movement of chromosomes
b) Cytoplasmic cleavage
c) Replication of DNA
d) Chromosome segregation

3) Which one of the following represents the best stage in which to view the shape, size and number of chromosomes?
a) Interphase
b) Telophase
c) Prophase
d) Metaphase

4) During cell divisions in the apical meristem the nuclear envelope appears in
a) Metaphase
b) Anaphase
c) Telophase
d) Cytokinesis

5) In which state is the chromosome thin and long and thread-like?
a) Leptotene
b) Zygotene
c) Pachytene
d) Diakinesis

6) How many mitotic divisions are required for a single cell to form 128 cells?
a) 7
b) 14
c) 28
d) 64

7) How many pollen grains can be formed after meiotic division in 10 microspore mother cells?
a) 80
b) 40
c) 20
d) 10

8) The number of chromatids in a chromosome at metaphase is
a) 2 in mitosis and 1 in meiosis
b) 1 in mitosis and in meiosis
c) 2 each in mitosis and meiosis
d) 2 in mitosis and 4 in meiosis

9) What ratio of homozygous to heterozygous is developed in the F2 progeny of a self fertilized monohybrid?
a) 3 : 1
b) 1 : 2 : 1
c) 2 : 2
d) 9 : 3 : 3 : 1

10) A dihybrid cross proves
a) The law of segregation
b) The law of purity of gametes
c) The law of dominance
d) The law of independent assortment

11) The cross used to ascertain whether the plant is homozygous or heterozygous is a
a) Linkage cross
b) Reciprocal cross
c) Back cross
d) Monohybrid cross

12) The phenomenon in which an allele of one gene suppresses the activity of an allele of another gene is known as
a) Dominance
b) Inactivation
c) Epistatis
d) Suppression

13) Alleles that produce independent effects in the heterozygous condition are called
a) Supplementary alleles
b) Codominant alleles
c) Epistatic alleles
d) Complementary alleles

14) The law of independent assortment can be related to one of the following:
a) Both homologous chromosomes of each pair are received by a single

b) The genes present on the same chromosome are randomly redistributed
c) The non-homologous chromosomes show random distribution during Anaphase-1 of meiosis
d) The exchange of segments between the non-homologous chromosomes

15) The factors which represent the contrasting pairs of characters are

a) Dominant recessive
b) Alleles
c) Homologous pairs
d) Determinants

16) According to the law of independent assortment, in a dihybrid cross
c) there is a single individual which is homozygous recessive for both the characters
d) it is not possible to forecast the different phenotypes

17) How many types of gametes are expected from an organism with the genotype AA BB CC?
a) One
b) Two
c) Four
d) Eight

18) How would you test a pea plant to see whether it is pure or hybrid for tallness?
a) Cross it with another tall pea plant of unknown genotype
b) Cross it with a pure tall pea plant
c) Cross with a homozygous dwarf pea
d) Cross it with any pea plant

19) At which stage is the fate of the genetic constitution of gametes finally

a) Metaphase-I
b) Anaphase-I
c) Anaphase-II
d) Diakinesis

20) The phenomenon which defies the law of independent assortment is
a) Segregation
b) Crossing over
c) Dominance
d) Linkage

21) An example of a quantitative trait in man is
a) Hair colour
b) Colour of eye
c) Skin colour
d) Shape of nose

22) Mendel was successful in formulating the laws of inheritance because
a) He studied one clear-cut character at a time
b) The characters studied by him were present on separate chromosomes
c) He chose correct experimental material
d) He kept accurate records of his experiments

23) Mendel is popularly known for postulating the
a) Origin of species
b) Cell theory
c) Linkage theory
d) Laws of inheritance

24) A cross between unlike organisms is called a
a) Test-cross
b) Back-cross
c) Heterosis
d) Hybrid

25) Genes do not occur in pairs in a
a) Zygote
b) Somatic cell
c) Endosperm cell
d) Gamete

26) Genetics deals with
a) Heredity and variation
b) Heredity
c) Mutations
d) Nuclear and cytoplasmic inheritance

27) A gene that shows its effect on more than one character is a
a) Polygene
b) Pleiotropic gene
c) Multifactor gene
d) Multiple gene

28) A dominant lethal gene is one which
a) Determines sex of offspring
b) Allows the organism to survive but not to reproduce
c) Allows the organisms to survive and reproduce
d) Kills the organism

29) The body features are
a) The phenotype
b) The genotype
c) The sex of the individual
d) Controlled by the environment

30) The ABO blood group system is due to
a) Multifactor inheritance
b) Incomplete dominance
c) Multiple alleles
d) Epistasis

31) The allele which is unable to express its effect in the presence
of another is called

a) Codominant
b) Supplementary
c) Complementary
d) Recessive

32) Blue eye colour is recessive to brown eye colour. A brown eyed man
whose mother was blue-eyed marries a blue-eyed woman. The children
will be

a) Both blue eyed and brown eyed 1:1
b) All brown eyed
c) All blue eyed
d) Blue eyed and brown eyed 3:1

33) Mendel did not propose
a) Dominance
b) Incomplete dominance
c) Segregation
d) Independent assortment

34) Female AaBb is crossed to male Aabb. The gametes will be
a) Female AB and ab, male AA and bb
b) Female Aa and Bb, male AA and bb
c) Female AB and ab, male Ab
d) Female AB, Ab, aB and ab, male Ab, ab

35) The genotype of
individuals can be tested by

a) Backcross with a homozygous recessive parent
b) Reciprocal crossing
c) Backcrossing with a heterozygous parent
d) Backcrossing with a homozygous dominant parent

36) An organism with identical alleles is
a) Dominant
b) Hybrid
c) Heterozygous
d) Homozygous

37) The contrasting pairs of factors in Mendelian crosses are called
a) Multiple alleles
b) Allelomorphs
c) Alloloci
d) Paramorphs

38) Mendel formulated the law of purity of gametes on the basis

a) Test cross
b) Back cross
c) Monohybrid cross
d) Dihybrid cross

39) One gene pair hides the effect of another. This phenomenon is
a) Epistasis
b) Dominance
c) Mutation
d) None of above

40) Gene A and B are necessary for normal hearing. What is the possible
genotype of a normal child born to a deaf mother and father?

a) aabb
b) AaBb
c) AaBB
d) Aabb

41) Hybrids are generally superior to the parent due to
a) Heterosis
b) Homozygosity
c) Heterozygosity
d) Parents are generally weak

42) Mendel’s work was rediscovered in
a) 1756
b) 1865
c) 1900
d) 1910

43) Blood grouping in human beings is controlled by
a) 4 alleles in which A is dominant
b) 3 alleles in which A and B are codominant and i is recessive
c) 3 alleles in which none is dominant
d) 3 alleles in which A is dominant

44) In humans, height shows a lot of variation. It is an example

a) Multiple alleles
b) Pleiotropic inheritance
c) Polygenic inheritance
d) Pseudoalleles

45) Genes located on the same locus but having different expressions

a) Multiple alleles
b) Oncogenes
c) Polygenes
d) Codominants

46) Four daughter cells obtained from a single meiosis
differ from one another because of

a) Crossing over
b) Independent assortment
c) Change in chromosome number
d) Both A and B

47) The favourite and ideal material for research
in genetics is the

a) Housefly
b) Mosquito
c) Frog
d) Fruit fly

48) Mendel selected the pea plant as the material for his experiments because
a) It is an annual plant with a comparatively short life cycle.
b) The flowers are self-pollinated
c) The number of seeds produced is quite large
d) All the above

49) One of the following did not constitute the seven contrasting pairs of characters
noticed by G.J. Mendel in the pea:

a) Height of the plants
b) Shape of the leaves
c) Shape of pod
d) Colour of pod

50) In genetics the term test cross means

51) Who is regarded as the

a) Gregor Johann Mendel
b) Morgan
c) Lamarck
d) Hugo de Vries

52) The number of different types of gametes produced from a plant with genotype
Aa Bb Cc is

a) 2
b) 8
c) 4
d) 16

53) The Mendelian principle which has always stood true is
a) The law of independent assortment
b) The law of segregation
c) The law of dominance
d) All the above

54) In Mirabilis jalapa when two pink flowered plants were crossed with each other, the generation produced 40 red, 80 pink and 40 white flow
a) Duplicate genes
b) Lethal genes
c) Incomplete dominance
d) Epistasis

55) The term genetics was coined by
a) Mendel
b) Bateson
c) Muller
d) Morgan

56) A tobacco plant heterozygous for albinism (a recessive character)
is self pollinated and 1200 seeds are subsequently germinated.
How many seedlings would have the parental genotype?

a) 900
b) 600
c) 1200
d) 300

laws were rediscovered by

a) Lamarck, de Vries and Correns
b) Hugo de Vries, Correns and Tschermak
c) Morgan, Beadle and Tatum
d) Hugo de Vires, Morgan and Correns

58) Multiple alleles are present
a) At different loci in the same chromosome
b) In different chromosome
c) At the same locus in homologous chromosomes
d) None of the above

59) The law of segregation of characters is also called
the law of purity of gametes because

a) Gametes have only one of the two alleles for each character
b) Gametes cannot be contaminated
c) Gametes are very different type of cells
d) It was another accidental term

60) The genes for the same trait present on nonhomologous
chromosomes are

a) Alleles
b) Linked genes
c) Multiple alleles
d) None of these

61) Blue eye colour in humans is recessive to brown
eye colour. The expected children of a marriage
between a blue eyed woman and a brown eyed man
who has a blue eyed mother will be

a) All blue eyed
b) All brown eyed
c) All black eyed
d) One blue eyed and one brown eyed

62) Segregation of genes takes place during
a) Metaphase II
b) Anaphase I
c) Prophase I
d) Embryo formation

63) A cross between a hybrid and a parent is known
as a

a) Test cross
b) Back cross
c) Monohybrid cross
d) Reciprocal cross

64) ABO blood grouping in humans is an example

a) Polygenic inheritance
b) Multifactor inheritance
c) Pleiotropic gene
d) Multiple alleles

65) In a multiple allele system a gamete possesses
a) Two alleles
b) Three alleles
c) One allele
d) Several alleles

66) ABO blood grouping shows
a) Codominant genes
b) Polygenes
c) Dominant-recessive genes
d) Both codominant and dominant recessive genes

67) A pleiotropic gene is one which
a) Affects one character
b) Affects more than one character
c) Supplements the effect of another gene
d) Requires another gene for expression

68) The spread of genes from one breeding
population to another by migration which
may result in changes in gene frequency
is called

a) Genetic Drift
b) Gene flow
c) Gene frequency
d) None of the above

69) A genetic clone is a
a) Plant produced by asexual means
b) Hybrid produced by sexual means
c) Homozygous plant produced by sexual means
d) Heterozygous plant produced by sexual means

70) Marriage between close relatives
should be avoided because it induces

a) Recessive alleles to come together
b) Mutations
c) Multiple births
d) Blood group abnormalities

71) Lethal genes are
a) Causative for appearance of ancestral traits
b) Always recessive
c) Genes present on different chromosomes but influencing single trait
d) Killers in the homozygous state

72) The term chromosome was coined by
a) Hofmeister
b) Sutton
c) Boveri
d) Waldeyer

73) Chromosomes were first seen by
a) Hofmeister
b) Waldeyer
c) Strasburger
d) Fleming

74) The chromosomes found in the salivary gland of Drosophila are
a) lampbrush
b) Polytene
c) Supernumerary
d) B-chromosome

75) A giant chromosome with a number of chromonemata is a
a) Lampbrush chromosome
b) Heterochromosome
c) Supernumerary chromosome
d) Polytene chromosome

76) Lampbrush chromosomes occur in the
a) Salivary gland
b) Lymph gland
c) Cancer cells
d) Oocytes

77) Chromosome ends are called
a) Satellite
b) Telomeres
c) Centromeres
d) Kinetochores

78) A chromatid is
a) One half of a chromosome
b) A haploid chromosome
c) A complete chromosome
d) A duplicate chromosme

79) The centromere is that part of the chromosome where
a) Nuclei are formed
b) Crossing over takes place
c) Chromatids are attached
d) Nicking occurs

80) A chromosome with a sub-terminal centromere is
a) Acentric
b) Acrocentric
c) Metacentric
d) Telocentric

81) A chromosome with a centromere near the middle is called
a) Metacentric
b) Submetacentric
c) Acrocentric
d) Telocentric

82) Puffs or Balbani rings in salivary glands chromosomes are sites of
a) DNA replication
b) DNA duplication
c) RNA synthesis
d) Protein synthesis

83) The chromosome theory of inheritance was proposed by
a) Sutton (1902)
b) Boveri (1902)
c) Both Sutton (1902) and Boveri (1902)
d) Correns (1909)

84) Chromatin fibres condense to form chromosomes during
b) S-phase
c) Telophase
d) Prophase

85) The preferred stage for counting of chromosomes is
a) Early prophase
b) Mid prophase
c) Late prophase
d) Metaphase

86) The genes which are present on the same chromosome are called
a) Identical genes
b) Allelomorphs
c) Linked genes
d) Dominant genes

87) Drosophila has four homologous pairs of chromosomes. What is the number of linkage groups in this animal?
a) Four
b) Two
c) Eight
d) Uncertain

88) The gene for color blindness in man is located on the
a) X chromosome only
b) Y chromosome only
c) Either X and Y chromosome
d) Both X and Y chromosome

89) A colour-blind daughter may be born if the
a) Father is normal and the mother is colour blind
b) Father is colour blind and the mother is normal
c) Father is normal and the mother is a carrier
d) Father is colour blind and the mother is a carrier

90) A normal woman is married to a colour blind man. The children are expected to be
a) All normal
b) 50% sons are colour blind
c) All daughters are normal but carrier whereas all sons are normal phenotypically as well as genotypically
d) 50% daughters are colour blind

91) Which of the following diseases is sex-linked?
a) Colour blindness
b) Malignancy
c) Hepatitis
d) Leukemia

92) A colour blind son is born to normal parents. It shows that
a) The father was heterozygous for colour blindness
b) The mother was genotypically homozygous
c) The mother was heterozygous for colour blindness
d) Both parents carried a recessive gene for the disorder

93) The chromosomal constitution in a human female can best be written as
a) 46

94) The points where the crossing over occurs between the homologous chromosomes of a pair are called
a) Centromeres
b) Chromomeres
c) Chromocentres
d) Chiasmata

95) Linkage in Drosophila was reported by
a) Mendel
b) Correns
c) Morgan
d) None of these

96) When two genes are situated very close to one another at a chromosome
a) The percentage of crossing over between them in very high
b) Hardly any cross-overs are produced
c) No crossing over can take place
d) Only double cross-overs can occur between them

97) The greater the distance between the two genes on a chromosome
a) The greater is the linkage strength
b) The lesser is the linkage strength
c) The linkage strength remains unchanged
d) There is no relationship between the two

98) Crossing over occurs at the
a) Single-strand stage of the chromosome during prophase
b) Two-strand stage during zygotene
c) Four-strand stage of pachytene
d) Metaphase II of meiosis

99) The term coupling and repulsion signify the same phenomenon which is termed
a) Synapsis
b) Disjunction
c) Linkage
d) Non-disjunction

100) A haemophiliac man marries a normal woman. What is the probability of the disease in the grand children in case the daughter marries a normal man?
a) All grandsons would be haemophiliac, and grand daughters normal
b) 50% of grandsons are haemophiliac. Other grand children are normal
c) Only grand daughters would be haemophiliac
d) All grand children would be haemophiliac



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