Chapter 3 Heredity And Common Genetic Diseases Multiple Choice Questions
Question 1. Following the monohybrid cross of Mendel if a hybrid tall (Tt) pea plant is crossed with a pure dwarf (tt) pea plant, what would be the percentage of hybrid tall pea plants in the first filial generation (F,)?
(1) 25 percent
(2) 50 percent
(3) 75 percent
(4) 100 percent.
Ans. The percentage of hybrid tall pea plants in the first filial generation (F,) will be 50 per cent.
Question 2. What will be the genotype ratio of a cross between hybrid tall pea plants (Tt) and dwarf pea plants (tt)?
(1) 1TT = 2Tt 1 tt
(2) 1Tt : 1tt
(3) 3Tt = Ite
(4) All Tt.
Answer: 1 Tt: 1 It will be the genotype ratio of a cross between hybrid tall pea
plants (Tt) and dwarf pea plants (tt).
Question 3. If a pure tall (TT) pea plant is crossed with a pure dwarf (tt) pea plant, what would be the percentage of hybrid tall pea plants in the first filial generation (F,) under the rule of mendels monohybrid cross?
(1) 15 percent
(2) 50 percent
(3) 75 percent
(4) 100 percent. :
Answer. The percentage of hybrid tall pea plants in the first filial generation (F,) by the rule of Mendel痴 monohybrid cross is 100 per cent.
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Question 4. The percentage of hybrid tall plants in F, generation produced from crossing two hybrid tall parental stocks is 4
(1) 25%
(2) 50%
(3) 75%
(4) 100%.
Answer. The percentage of hybrid tall plants in F, generation produced from crossing two hybrid tall parental stocks is 50%.
Question 5. The father of Genetics is
(1) Darwin
(2) Bateson
(3) Benda
(4) Mendel.
Answer. The father of Genetics is Mendel.
Question 6. A pair of contrasting characters is called
(1) Phenotype
(2) Genotype
(3) Gene
(4) Allele.
Answer. A pair of contrasting characters is called Allele.
Question 7. The character which predominates and is seen in F, generation is said to be ・
(1) Dominant
(2) Recessive
(3) Particular
(4) Special.
Answer. The character which predominates and is seen in the F, generation is said to be Dominant.
Question 8. The term gene was coined by p
(1) Morgan
(2) Weismann
(3) Lamarck
(4) Johannsen.
Answer. The term gene was coined by Johannsen.
Question 9. When two individuals are similar in external BRESAUSASE but different in their genetic make-up, they are called as
(1) Allele
(2) Pure
(3) Homozygous
(4) Heterozygous.
Answer. When two individuals are similar in external appearance but different in their genetic makeup, they are called Heterozygous.
Question 10. What would be the probable genotype of pure dwarf pea plant a
(1) Tt
(2) tt,
(3) TT,
(4) None of the above
Answer. The probable genotype of pure dwarf pea plant will be tt
Question 11. Mendel’s choice of contrasting characters from pea plants are
(1) 8 pairs
(2) 7 pairs
(3) 6 pairs
(4) 5 pairs
Answer. Mendel choice of contrasting characters from pea plants is 7 pairs.
Question 12. One pure red eyes Drosophila when crossed with pure white eyes Drosophila the offspring in F, generation will be found (when red is dominant over white)
(1) both red and white eyes,
(2) only red eyes,
(3) only white eyes.
(4) intermediate type of eyes.
Answer. One pure red eyes Drosophila when crossed with pure white eyes Drosophila the offspring in F, generation will found (when red is dominant over white) Only red eyes.
Question 13. When a hybrid black guinea pig is crossed with a pure white Guineapig the offspring of F, will be –
(1) 3:1
(2)1:2:1
(3)1:1
(4) None of them.
Answer. When a hybrid black guinea pig is crossed with a pure white Guinea pig the offspring of F, will be 1: 1.
Question 14. The phenotype result of Mendel’s dihybrid cross will be
(1)1:1:1:1
(2)9:3:3:1
(3)2:3:3:4:5
(4)1:2:3:4
Answer. The phenotype result of Mendel’s dihybrid cross will be 9: 3:3:1
Question 15. In dihybrid cross types of phenotypic offspring are produced in F, generation ・
(1) 2
(2) 5
(3) 6
(4) 4
Answer. In dihybrid cross types of phenotypic offspring are produced in F, generation 4.
Question 16. Hereditary component is
(1) Nucleus
(2) Chromosome
(3) DNA
(4) Protein
Answer. The hereditary component is DNA.
Question 17. Mendel’s experimental results were published in the year
(1) 1900
(2) 1866
(3) 1865
(4) 1864
Answer. Mendel’s experimental results were published in the year 1866.
Question 18. Like begets like is an important and universal phenomenon of life is due
(1) Genetics
(2) Eugenesis
(3) Morphology
(4) Embryology
Answer. Like begets like is an important and universal phenomenon of life due to
Genetics.
Question 19. Which one is a hereditary disease?
(1) Cataract
(2) Leprosy
(3) Blindness
(4) Phenylketonuria
Answer. Phenyl ketonuria is a hereditary disease.
Question 20. How many types of genotypes will be obtained in plants of the F, generation when two hybrid tall plants (Tt) are crossed?
(1) one type
(2) two types
(3) three types
(4) four types
Answer. Three types of genotypes will be obtained in plants of the F, generation when two hybrid tall plants (Tt) are crossed.
Question 21. The pea plants produced from the seeds obtained from a cross between hybrid tall (Tt) and pure dwarf (tt) pea plants will be
(1) All tall
(2) All dwarf
(3) 50% tall, 50% dwarf
(4) 75% tall, 25% dwarf.
Answer. The pea plants produced from the seeds obtained from a cross between hybrid tall (Tt) and pure dwarf (tt) pea plants will be 50% tall, and 50% dwarf.
Question 22. Following the monohybrid cross of Mendel if a hybrid tall (Tt) Pea plant is crossed with a pure dwarf (tt) pea plant, what would be the percentage of
hybrid tall pea plant in the first filial (F,) generation?
(1) 25%
(2) 50%
(3) 75%
(4) 100%
Answer. The percentage of hybrid tall pea plants in the first filial (F,) generation will be 50%
Question 23. Who is known as the father of Genetics・?
(1) Lamarck
(2) Darwin
(3) Hugo De vries
(4) Mendel.
Answer. Mendel is known as the father of Genetics・
Question 24. The genotypes of F, plants obtained by crossing two hybrids (Aa) plants will be
(1) One
(2) Two
(3) Three
(4) four.
Answer. The genotypes of F, plants obtained by crossing two hybrids (Aa) plants will be Three types.
Question 25. If hybridization is made between two aye tall pea plants; the hybrid tall pea plants in F, generation will be
(1) 25%
(2) 50%
(3) 75%
(4) 100%
Answer. If hybridization is made between two hybrid tall pea plants, the hybrid pea plants in F, generation will be 50%. ｩ
Question 26. The genetic constitution of an organism is
(1) Phenotype
(2) Genotype
(3) Genotype and Phenotype
(4) none of them.
Answer. The genetic constitution of an organism is genotype.
Question 27. The phenotypic ratio deduced from the Mendel dihybrid cross is
(1)3:1
(2)1:2:1
(3)9: 3:3: 1
(4)9:9:1
Answer. The phenotypic ratio deduced from the Mendel dihybrid cross is 9: 3:3: 1
Question 28. Inheritance of characters is discussed in a branch of science known as
(1) Cytology
(2) Genetics
(3) Evolution
(4) Adaptation
Answer. (2) Genetics
Question 29. The term Genetics・has been coined by
(1) Mendel
(2) Bateson
(3) Morgan
(4) Johansen
Answer. (2) Bateson
Question 30. Mendel did his experiment on a plant known as
(1) Bean Plant
(2) Wheat plant
(3) Paddy plant
(4) Pea plant
Answer. (4) Pea plant
Question 31. How many laws of inheritance were proposed by Mendel?
(1) One
(2) Two
(3) Three
(4) Four
Answer. (2) Two
Question 32. The F, phenotypic ratio of Mendel’s monohybrid cross is
(1)2:1
(2)3:1
(c)1:2:1
(4)9:4:3
Answer. (2) 3: 1
Question 33. In the dihybrid cross of Mendel the F, ratio obtained is
(1)9:3:3:1
(2) 9:7
(3)1:1:1
(4)9:4:3
Answer.(1)9:3:3:1
Question 34. What is the genotypic ratio of F, generation in Mendel’s monohybrid experiment?
(1)1:1
(2)2:1
(3)3:1
(4)1:2:1
Answer. (2) 2:1
Question 35. Who proposed the law of independent assortment?
(1) Darwin
(2) De Vries
(3) Mendel
(4) Lamarck
Answer. (3) Mendel
Question 36. The “tall” trait of the pea plant is
(1) Dominant
(2) Semidominant
(3) Recessive
(4) Codominant
Answer. (1) Dominant
Question 37. The cross between F, offspring and father or mother is known as
(1) Test cross
(2) Reciprocal cross
(3) Back cross
(4) None of the above
Answer. (3) Back cross
Question 38. What is meant by the 1: 1 ratio in the monohybrid cross?
(1) F, organism is homozygote
(2) F, organism is heterozygote
(3) F, organism is pure
(4) The ratio is produced due to back cross
Answer. (2) F, organism is heterozygote
Question 39. Which of the following is a test cross?
(1) Tt x tt
(2) tt x tt
(3) Tt Tt
(4) TT x TT
Answer. (1) Tt x tt
Question 40. Which of the following is a back cross?
(1) FX,
(2) F, x recessive
(3) FE, xP
(4) F, x any parent
Answer. (4) F, x any parent
Question 41. Which one of the following is the result of a monohybrid cross?
(1)1:1:1:1
(2) 9:3:3:1
(3) 3:1
(4)9:7
Answer: (3)3.: 1
Question 42. What is known as the unit of heredity?
(1) Genotype
(2) Phenotype
(3) Gene
(4) Protein
Answer. (3) Gene
Question 43. When two different alleles of a gene are present the organism is known as ・
(1) Heterozygote
(2) Homologous
(3) Homozygote
(4) Hemizygote
Answer. (1) Heterozgote
Question 44. When the pure yellow, round pea plant is crossed with a green wrinkled pea plant, the F, pea plant will be
(1) All yellow wrinkled
(2) 50% yellow round, 50% green wrinkled
(3) All yellow round
(4) 50% yellow wrinkled, 50% green round
Answer. (3) All yellow round
Question 45. When will all children of a couple be found colourblind?
(1) If the mother is normal and the father is normal
(2) If the mother is normal and the father is colourblind
(3) If the mother is homozygous colourblind and the father is normal
(4) If the mother is homozygous colourblind and the father is colourblind.
Answer. (4) If the mother is homozygous colourblind and the father is colourblind.
Question 46. The separation of linked genes occurs through
(1) Crossing over
(2) Segregation
(3) Mutation
(4) Linkage
Answer. (1) Crossing over
Question 47. Colourblind is a sex-linked recessive trait. If a mother is colourblind sons will be
(1) All colourblind
“(2) All normal vision
(3) 50% colourblind, 50% normal
(4) None of the above
Answer. (1) All colourblind
Question 48. Which of the following conditions is related to haemophilia?
(1) A responsible recessive gene present in the X chromosome
(2) A responsible dominant gene present in the X chromosome
(3) A responsible dominant gene present in the Y chromosome
(4) A responsible dominant gene present in the autosomal chromosome
Answer. (1) A responsible recessive gene present in the X chromosome
Question 49. In seven pairs of contrasting characters in the pea plant studied by Mendel, the number of flower-based characters was
(1) 1
(2) 2
(3) 3
(4) 4
Answer. (2) 2 :
Question 50. In Mendel’s experiment, how many different kinds of seeds are produced from a short plant with wrinkled seeds (ttrr)?
(1) 9
(2) 4
(3) 2
(4) 1
Answer.(4) 1
Question 51. A cross between a dominant phenotype with the recessive parent to check its genotype is called
(1) Test cross
(2) Back cross
(3) Monohybrid cross
(4) Dihybrid cross
Answer. (1) Test cross
Question 52. Some of the dominant traits studied by Mendel were
(1) round seed shape, constricted pod shape and axial flower position
(2) green pod colour, inflated pod shape and axial flower position
(3) yellow seed colour, violet flower colour and yellow pod colour
(4) axial flower position, green pod colour and green seed colour
Answer. (2) green pod colour, inflated pod shape and axial flower position
Question 53. The colour-based contrasting traits in several contrasting pairs studied by Mendel in pea plants were
(1) 1
(2) 2
(3) 3
(4) 4
Answer. (3) 3
Question 54. The mechanism of transmission of characters, resemblances as well as difference, from the parental generation to the offspring is called
(1) Astrology
(2) Heredity
(3) Coincidence
(4) Nurture
Answer. (2) Heredity
Question 55. One of the scientists who rediscovered Mendelism was
(1) Bateson
(2) Darwin
(3) Tschermak
(4) Lamarck
Answer. (3) Tschermak
Question 56. is a change in a gene or chromosome.
(1) Evolution
(2) Variation
(3) Heredity
(4) Mutation
Answer. (4) Mutation
Question 57. The ability of tongue rolling is controlled by–
(1) Practice
(2) Gene
(3) Environment
(4) Temperature
Answer. (2) Gene
Question 58. An is an alternative form of gene.
(1) Allele
(2) Locus
(3) Genotype
(4) Phenotype
Answer. (1) Allele
Question 59. The place of location of a gene is called
(1) House
(2) Niche
(3) Locus
(4) Chromosome
Answer. (3) Locus
Question 60. means that the organism has two copies of the same allele for a gene.
(1) Hetergogygous
(2) Hemizygous
(3) Homozygous
(4) Hybrid
Answer. (3) Homozygous
Question 61. Genes are present in a sequence on the chromosomes
(1) Serial
(2) Linear
(3) Circular
(4) Haphazard
Answer. (2) Linear
Question 62. means that an organism has two different alleles of a gene.
(1) Hemizygous
(2) Heterozygous
(3) Homozygous
(4) Allozygous
Answer. (2) Heterozygous
Question 63. A genetic hybrid would carry two different of the same gene.
(1) Cocus
(2) Numbas
(3) Types
(4) Allejes
Answer. (4) Alleles
Question 64. The generation is the first set of parents crossed.
(1) Parental
(2) Filial
(3) Hybrid
(4) Mother
Answer. (1) Parental
Question 65. The Scientific name of the four o’clock plant is mirabilis
(1) Indicus
(2) Jalapa
(3) Domestica
(4) Bengalensis
Answer, (2) Jalapa
Question 66. The sex chromosomes of human males are
(1) XX
(2) AA
(3) XY
(4) PQ
Answer. (3) XY
Question 67. Thalassemia is an autosomal trait.
(1) Dominant
(2) Recessive
(3) Sexlinked
(4) Poisonous
Answer. (2) Recessive
Question 68. Haemophilic persons have problems with blood
(1) Pigmentation
(2) Clotting
(3) Colour
(4). Temperature
Answer. (2) Clotting
Question 69. Red colour blindness is the most common.
(1) Green
2) Blue
(3) Black
(4) Yellow
Answer. (1) Green
Question 70. Genes do not occur in pairs in
(1) Endosperm
(2) Zygote
(3) Gametes
(4) Somatic cells
Answer. (3) Gametes
Question 71. The phenomenon which defines the independent assortment is
(1) Segregation
(2) Dominance
(3) Crossing over
(4) Linkage
Answer. (1) Segregation
Question 72. A haploid set of all the genes present in a gametes is called
(1) Genome
(2) Linkage group
(3) Phenotype
(4) Genotype
Answer. (1) Genome
Question 73. Who first used the termene?
(1) Mendel
(2). Johannsen
(3) Bateson
(4) Morgan
Answer. (2) Johannsen
Question 74. Incomplete dominance is observed in
(1) Hibiscus
(2) Mirabilis
(3) Sunflower
(4) Roulfia
Answer. (2) Mirabilis Jalpa (4 0・clock plant)
Question 75. What will be the percentage of hybrid tall plants produced in F, generation due to hybridisation between two hybrid tall pea plants?
(1) 100%
2) 75%
(3) 50%
(4) 25%
Answer. (3) 50%
Question 76. The phenotypic ratio of F, generation in Mendel’s dihybrid cross is-
(1)1:2:1
(2) 9:3:3:1
(3)1:3
(4)1:1
Answer. (6) 9:23:31
Question 77. All the genes present in interbreeding populations are together known as
(1) Genone
(2) Gene pool
(3) Chromosome
(4) None
Answer. (2) Gene pool
Question 78. The law derived from the dihybrid cross is
(1) Law of dominance
(2) Law of segregation
(3) Law of independent assortment
(4) All of these
Answer. (3) Law of independent assortment
Question 79. An alternative form of gene is-
(1) Chromosome
(2) Allele
(3) Character
(4) None
Answer. (2) Allele
Question 80. The combination of genes in an organism is-
(1) Phenotype
(2) Genotype
(3) Variation
(4) All
Answer. (2) Genotype
Question 81. The total loss of skin pigment in a body is called
(1) Leukemia
(2) Colour blindness
(3) Albinism
(4) Haemophilia
Answer. (3) Albinism
Question 82. A blood disease caused by gene mutation is-
(1) Anaemia
(2) Sickle cell anaemia
(3) Albinism
(4) Malaria
Answer. (2) Sickle cell anaemia
Question 83. An X-linked disease is
(1) Anaemia
(2) Haemophilia
(3) Malaria
(4) All of the above
Answer. (2) Haemophilia
Question 84. Small differences among individuals are called
(1) Variation
(2) Mutation
(3) Evolution
(4) All of these
Answer. (1) Variation
Question 85. The technique in which the genetic constitution of an organism is altered by introducing a new gene is-
(1) Genetic counselling
(2) Genetic engineering
(3) Heredity
(4) None of these
Answer. (2) Genetic engineering
Question 86. A genetic disease is
(1) Haemophilia
(2) Thalassemia
(3) Colourblindness
(4) All of the above
Answer. (4) All of the above
Question 87. The operation of removal of anthers is known as
(1) Pollination
(2) Fertilization
(3) Emasculation
(4) Selection
Answer. (3) Emasculation
Question 88. The cross between F, hybrid and recessive homozygous parent is called
(1) Back cross :
(2) Test cross
(3) Self cross
(4) Monohybrid cross
Answer. (2) Test cross
Question 89. Sex-linked inheritance was first discovered by
(1) Mendel
(2) Punnet
(3) Johansen
(4) T.H. Morgan
Answer. (4) T.H. Morgan
Question 90. The functional unit of DNA molecule is called
(1) Recon
(2) Cistron
(3) Muton
(4) All of these
Answer. (2) Cistron
Question 91. A common hereditary disorder which is carried on by autosomes is-
(1) Jurner’s syndrome
(2) Klinefelter’s syndrome
(3) Down syndrome
(4) a and b
Answer. (3) Down syndrome
Question 92. The genotypic ratio of the monohybrid cross is
(1)3:1
(2)1:2:1
(3)2:2
(4) 1:3
Answer. (2)1:2:1
Question 93. A ‘Y-chromosome-linked character in males is
(1) Hypertrichosis of ears
(2) Pattern baldness
(3) Both (1) and (2)
(4) None of these
Answer. (3) Both (1) and (2)
Chapter 3 Heredity And Common Genetic Diseases Fill In The Blanks
Question 1. is one of the discoverers of Mendelism.
Answer. Hugo De vries.
Question 2. The study of heredity is called
Answer. genetics.
Question 3. The pair of contrasting characters are called
Answer. Alleles.
Question 4. is the father of heredity.
Answer. G J. Mendel.
Question 5. The unit of heredity is
Answer. gene.
Question 6. The phenotypic ratio of the monohybrid cross is
Answer. 3:1.
Question 7. The genotypic ratio of the monohybrid cross is
Answer. 1:2:1.
Question 8. The genetic constitution of an individual is called
Answer. genotype.
Question 9. If the pure tall and the pure dwarf plants are crossed, all the plants produced in F, generation would be
Answer. hybrid.
Question 10. The plant on which the monohybrid experiment was conducted by Mendel is:
Answer. Sweet pea.
Question 11. Among the pairs of contrasting characters, Mendel noted smooth seed as against seed.
Answer. rough.
Question 12. The law of segregation is otherwise known as the law of
Answer. purity of gametes.
Question 13. is regarded as the father of genetics
Answer. Mendel.
Question 14. The phenotype that expresses itself in the F, generation is known as
Answer. dominant.
Question 15. The law of independent assortment was the outcome of Mendel’s cross-experiment.
Answer. Dihybrid.
Question 16. In human beings, chromosomes are responsible for maleness.
Answer. Y.
Question 17.9:3:3:1F, the ratio is the outcome of Mendel’s cross.
Answer. dihybrid.
Question 18. In dihybrid F, plants produce types of gametes.
Answer. 4.
Question 19. Genes in a chromosome are arranged in an order.
Answer. linear.
Question 20. Gene is composed of nucleic acid.
Answer. DNA.
Question 21. Scientists first described linkage in Drosophila.
Answer. Morgan
Question 22. The law of Mendel obtained from the monohybrid cross is known as the law of are.
Answer. Segregation
Question 23. From the dihybrid cross, Mendel derived the law of
Answer. Independent Assortment
Question 24. Mendel worked on pairs of contrasting characters.
Answer. 7
Question 25. The dwarf character of the pea plant is a character.
Answer. Recessive
Question 26. is the phenotypic F, ratio obtained from monohybrid cross.
Answer. 3: 1
Question 27. The colourblind gene is located on the chromosome.
Answer. X
Question 28. If the ratio of test cross result is 1: 1, the parental genotype will be 2nA,
Ans. Heterozygous
Question 29. The same genotypic and phenotypic F, ratio is found in the case of gene.
Answer. Semidominant
Question 30. If the mother is colourblind the phenotype of the sons will be
Answer. All colourblind
Question 31. If the mother is a carrier of haemophilia, the sons will be
Answer. 50% normal, 50% haemophilic
Chapter 3 Heredity And Common Genetic Diseases True Or False
Question 1. Mendel worked on principles of classification.
Answer. false
Question 2. Mendel derived his second law as the law of segregation.
Answer. false
Question 3. From the dihybrid cross, Mendel derived his law of independent assortment
Answer. True
Question 4. Colour blindness is an autosomal recessive trait.
Answer. false
Question 5. Thalassemia is an autosomal trait.
Answer. True
Question 6. There is a skip of generations in the case of dominant pedigree.
Answer. false
