Principles of Inheritance and Variation (last 10 years)

Question 1

1. Given below are two statements:

Statement I: Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of Inheritance.

Statement II: Seven characters examined by Mendel in his experiment on pea plants were seed shape and colour, flower colour, pod shape and colour, flower position and stem height.

In the light of the above statements, choose the correct answer from the options given below. (2022)

a. Statement I is incorrect but Statement II is correct
b. Both Statement I and Statement II are correct
c. Both statement I and statement II are incorrect
d. Statement I is correct but Statement II is incorrect

Question 2

2. The production for gametes by the parents, formation of zygotes, the F1 and F2 plants,can be understood from a diagram called: (2021)

a. Punch square
b. Punnett square
c. Net square
d. Bullet square

Question 3

3. Identify the wrong statement with reference to the gene ‘I’ that controls ABO blood groups. (2020)

a. A person will have only two of the three alleles.
b. When IA and IB are present together, they express same type of sugar.
c. Allele ‘i’ does not produce any sugar
d. The gene I has three alleles.

Question 4

4. How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits? (2020)

a. 2
b. 14
c. 8
d. 4

Question 5

5. The number of contrasting characters studied by Mendel for his experiments was: (2020-Covid)

a. 4
b. 2
c. 7
d. 14

Question 6

6. In Antirrhinum (Snapdragon), a red flower was crossed with a white flower and in F1 generation pink flowers were obtained. When pink flowers were selfed, the F2 generation
   showed white, red and pink flowers.

Choose the incorrect statement from the following : (2019)

Question 7

7. Which of the following characteristics represent ‘Inheritance of blood groups’ in humans? (2018)

A. Dominance
B. Co-dominance
C. Multiple alleles
D. Incomplete dominance
E. Polygenic inheritance

a. B, C and E
b. A, B and C
c. B, D and E
d. A, C and E

Question 8

8. Among the following characters, which one was not considered by Mendel in his experiments on pea? (2017-Delhi)

a. Stem – Tall or Dwarf
b. Trichomes – Glandular or non-glandular
c. Seed – Green or Yellow
d. Pod – Inflated or Constricted

Question 9

9. The genotypes of a Husband and Wife are IAIB and IAi. Among the blood types of their children, how many different genotypes and phenotypes are possible? (2017-Delhi)

a. 3 genotypes ; 3 phenotypes
b. 3 genotypes ; 4 phenotypes
c. 4 genotypes ; 3 phenotypes
d. 4 genotypes ; 4 phenotypes

Question 10

10. Which one from those given below is the period for Mendel’s hybridization experiments?
    (2017-Delhi)

a. 1856 - 1863
b. 1840 - 1850
c. 1857 - 1869
d. 1870 - 1877

Question 11

11. A true breeding plant is: (2016 - II)

a. Nearly homozygous and produces offspring of its own kind
b. Always homozygous recessive in its genetic constitution
c. One that is able to breed on its own
d. Produced due to cross-pollination among unrelated plants

Question 12

12. In a test cross involving F1 dihybrid flies, more parentaltype offspring were produced than the recombinant-type offspring. This indicates (2016 - I)

a. The two genes are located on two different chromosomes
b. Chromosomes failed to separate during meiosis
c. The two genes are linked and present on the same chromosome
d. Both of the characters are controlled by more than one gene

Question 13

13. A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes were in the ratio of: (2016 - I)

a. 1 : 2 : 1 : Tall homozygous : Tall heterozygous : Dwarf
b. 1 : 2 : 1 : Tall heterozygous : Tall homozygous : Dwarf
c. 3 : 1 : Tall : Dwarf
d. 3 : 1 : Dwarf : Tall

Question 14

14. How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments? (2016 - I)

a. Eight
b. Seven
c. Five
d. Six

Question 15

15. A man with blood group ‘A’ marries a woman with blood group ‘B’. What are all the possible blood groups of their offspring’s? (2016 - I)

a. A, B, AB and O
b. O only
c. A and B only
d. A, B and AB only

Question 16

16. Multiple alleles are present: (2015)

a. At the same locus of the chromosome
b. On non-sister chromatids
c. On different chromosomes
d. At different loci on the same chromosome

Question 17

17. Alleles are: (2015)

a. Different molecular forms of a gene
b. Heterozygote’s
c. Different phenotype
d. True breeding homozygote’s

Question 18

18. A gene showing co-dominance has: (2015 Re)

a. Alleles tightly linked on the same chromosome
b. Alleles that is recessive to each other
c. Both alleles independently expressed in the heterozygote
d. One allele dominant on the other

Question 19

19. In his classic experiments on pea plants, Mendel did not use: (2015 Re)

a. Pod length
b. Seed shape
c. Flower position
d. Seed colour

Question 20

20. If two persons with ‘AB’ blood group marry and have sufficiently large number of children, these children could be classified as ‘A’ blood group : ‘AB’ blood group : ‘B’ blood group in 1 : 2 : 1 ratio. Modern technique of protein electrophoresis reveals presence of both ‘A’ and ‘B’ type
    proteins in ‘AB’ blood group individuals. This is an example of: (2013)

a. Complete dominance
b. Co-dominance
c. Incomplete dominance
d. Partial dominance

Question 21

22. Fruit colour in squash is an example of: (2014)

a. Inhibitory genes
b. Recessive epistasis
c. Dominant epistasis
d. Complementary genes

Question 22

21. Which Mendelian idea is depicted by a cross in which the F1 generation resembles both the parents? (2013)

a. Co-dominance
b. Incomplete dominance
c. Law of dominance
d. Inheritance of one gene

Question 23

23. Experimental verification of the chromosomal theory of inheritance was done by: (2020)

a. Sutton
b. Boveri
c. Morgan
d. Mendel

Question 24

24. Chromosomal theory of inheritance was proposed by: (2020-Covid)

a. Bateson and Punnet
b. T.H. Morgan
c. Watson and Crick
d. Sutton and Boveri

Question 25

25. What map unit (Centimorgan) is adopted in the construction of genetic maps? [Os] (2019)

a. A unit of distance between two expressed genes representing 10% cross over.
b. A unit of distance between two expressed genes representing 100% cross over.
c. A unit of distance between genes on chromosomes, representing 1% cross over.
d. A unit of distance between genes on chromosomes, representing 50% cross over.

Question 26

26. Given below are two statements: one is labelled as Assertion

(A) and the other is labelled as Reason (R).

Assertion (A): Mendel’s law of Independent assortment does not hold good for the genes that are located closely one the same chromosome.

Reason (R): Closely located genes assort independently.

In the light of the above statements, choose the correct answer from the options given below. (2022)

a. (A) is not correct but (R) is correct
b. Both (A) and (R) are correct and (R) is the correct explanation of (A)
c. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
d. (A) is correct but (R) is not correct

Question 27

27. The best example for pleiotropy is: (2020-Covid)

a. Phenylketonuria
b. Colour Blindness
c. ABO Blood group
d. Skin colour

Question 28

28. The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by (2019)

a. T.H. Morgan
b. Gregor J. Mendel
c. Alfred Sturtevant
d. Sutton Boveri

Question 29

29. Select the correct statement: (2018)

a. Franklin Stahl coined the term “linkage”.
b. Punnett square was developed by a British scientist.
c. Spliceosomes take part in translation.
d. Transduction was discovered by S. Altman.

Question 30

30. Match the terms in Column-I with their description in Column-II and choose the correct option (2016 - I)Column-I Column-II
    A. Dominance i. Many genes govern a single character
    B. Co-dominance ii. In a heterozygous organism only one allele expresses itself
    C. Pleiotropy iii. In a heterozygous organism both alleles express themselves fully
    D. Polygenic inheritance iv. A single gene influences many characters

a. A-(ii), B-(i), C-(iv), D-(iii)
b. A-(ii), B-(iii), C-(iv), D-(i)
c. A-(iv), B-(i), C-(ii), D-(iii)
d. A-(iv), B-(iii), C-(i), D-(ii)

Question 31

31. The movement of a gene from one linkage group to another is called: (2015)

a. Translocation
b. Crossing over
c. Inversion
d. Duplication
assortment

Question 32

32. The term “linkage” was coined by: (2015 Re)

a. T. Boveri
b. G. Mendel
c. W. Sutton
d. T.H. Morgan

Question 33

33. A pleiotropic gene: (2015 Re)
    a. Is a gene evolved during Pliocene
    b. Controls a trait only in combination with another gene
    c. Controls multiple traits in an individual
    d. Is expressed only in primitive plants

Question 34

34. Which of the following statements is not true for two genes that show 50% recombination frequency? (2013)

a. If the genes are present on the same chromosome, they
undergo more than one crossover in every meiosis
b. The genes may be on different chromosomes
c. The genes are tightly linked
d. The genes show independent

Question 35

35. Select the incorrect statement. (2019)

a. Male fruit fly is heterogametic
b. In male grasshoppers 50% of sperms have no sexchromosome
c. In domesticated fowls, sex of progeny depends on the type of sperm rather than egg
d. Human males have one of their sex-chromosome much shorter than the other

Question 36

36. Which of the following pairs is wrongly matched? (2018)

a. Starch synthesis in pea : Multiple alleles
b. ABO blood grouping : Co-dominance
c. XO type sex determination : Grasshopper
d. T.H. Morgan : Linkage

Question 37

37. An abnormal human baby with ‘XXX’ sex chromosomes was born due to: (2015)

a. Fusion of two ova and one sperm
b. Fusion of two sperms and one ovum
c. Formation of abnormal sperms in the father
d. Formation of abnormal ova in the mother

Question 38

38. Which of the following occurs due to the presence of autosome linked dominant trait? (2022)

a. Thalessemia
b. Sickle cell anaemia
c. Myotonic dystrophy
d. Haemophilia

Question 39

39. If a colour blind female marries a man whose mother was also colour blind, what are the chances of her progeny having colour blindness? (2022)

a. 100%
b. 25%
c. 50%
d. 75%

Question 40

40. In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased? (2021)

a. 75%
b. 25%
c. 100%
d. 50%

Question 41

41. Select the correct match (2020)

Column-I Column-II

a. Phenylketonuria: Autosomal dominant trait
b. Sickle cell anaemia: Autosomal recessive trait, chromosome-11
c. Thalassemia : X linked
d. Haemophilia: Y linked

Question 42

42. What is the genetic disorder in which an individual has an overall masculine development gynaecomastia, and is sterile? (2019)

a. Turner’s syndrome
b. Klinefelter’s syndrome
c. Edward syndrome
d. Down’s syndrome

Question 43

43. A woman has an X-linked condition on one of her X chromosomes.
    This chromosome can be inherited by: (2018)

a. Only daughters
b. Only sons
c. Only grandchildren
d. Both sons and daughters

Question 44

44. A disease caused by an autosomal primary non-disjunction is (2017-Delhi)

a. Down’s syndrome
b. Klinefelter’s syndrome
c. Turner’s syndrome
d. Sickle cell anemia

Question 45

45. Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement. (2017-Delhi)

a. Both are due to a qualitative defect in globin chain synthesis
b. Both are due to a quantitative defect in globin chain synthesis
c. Thalassemia is due to less synthesis of globin molecules
d. Sickle cell anemia is due to a quantitative problem of globin molecules

Question 46

46. If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is: (2016 - II)

a. 0.75
b. 1
c. 0
d. 0.5

Question 47

47. Pick out the correct statements: (2016 - I)

A. Haemophilia is a sex-linked recessive disease.
B. Down’s syndrome is due to aneuploidy.
C. Phenylketonuria is an autosomal recessive gene disorder.
D. Sickle cell anaemia is an X-linked recessive gene disorder.

a. (A) and (D) are correct
b. (B) and (D) are correct
c. (A), (C) and (D) are correct
d. (A), (B) and (C) are correct

Question 48

48. Which of the following most appropriately describes haemophilia? (2016 - I)

a. Recessive gene disorder
b. X-linked recessive gene disorder
c. Chromosomal disorder
d. Dominant gene disorder

Question 49

49. In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree. (2015 Re)

Insert the image

a. X-linked recessive
b. Autosomal recessive
c. X-linked dominant
d. Autosomal dominant

Question 50

50. A colour blind man marries a woman with normal sight who has no history of colour blindness in her family. What is the probability of their grandson being colour blind? (2015 Re)

a. 1
b. Nil
c. 0.25
d. 0.5

Question 51

51. A human female with Turner’s syndrome: (2014)

a. Is able to produce children with normal husband
b. Has 45 chromosomes with XO
c. Has one additional X chromosome
d. Exhibits male characters

Question 52

53. The incorrect statement with regard to Haemophilia is: (2013)

a. A single protein involved in the clotting of blood is affected
b. It is a sex - linked disease
c. It is a recessive disease
d. It is a dominant disease

Question 53

52. A man whose father was colour blind marries a woman who had a colour blind mother and normal father. What percentage of male children of this couple will be colour blind? (2014)

a. 75%
b. 25%
c. 0%
d. 50%

Question 54

54. If both parents are carriers for Thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child? (2013)

a. 100%
b. No chance
c. 50%
d. 25%