NCERT CLASS 12 | TOPIC : PRINCIPLES OF INHERITANCE AND VARIATION | QB-3 | NEET BIOLOGY ONLINE TEST

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NCERT CLASS 12 | TOPIC : PRINCIPLES OF INHERITANCE AND VARIATION | QB-3 | NEET BIOLOGY ONLINE TEST

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It contains 91 important questions. Choose the most correct answer. Then check your answer. Try again if there are errors. Regards : www.onlinetest.kalvisolai.com

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1 ➤ 195. Mother and father of a person with ‘0’ blood group have ‘A’ and ‘B’ blood group, respectively. What would be the genotype of both mother and father?

(a) Mother is homozygous for ‘A’ blood group and father is heterozygous for ‘B’. (b) Mother is heterozygous for ‘A’ blood group and father is homozygous for ‘B’. (c) Both mother and father are heterozygous for ‘A’ and ‘B’ blood group, respectively. (d) Both mother and father are homozygous for ‘A’ and ‘B’ blood group, respectively.

2 ➤ 196. Assertion: Gregor Mendel conducted the hybridization experiment on garden peas and proposed the laws of inheritance in living organism.

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Reason: Mendel selected 7 true breeding pea plant varieties.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

3 ➤ 197. Assertion: In a monohybrid cross F1 generation indicates recessive characters.

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Reason: Dominance occurs only in homozygous state.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

4 ➤ 198. Assertion: Gene which code for a pair of contrasting traits are known alleles.

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Reason: Alleles are slightly different forms of the same gene.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

5 ➤ 199. Assertion: The law of dominance is used to explain the expression of only one of the parental character is a monohybrid cross in the F1 - generation.

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Reason: The law of dominance explains the propportion of 3 : 1 obtained at the F2 – generation.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

6 ➤ 200. Assertion: Deletions and insertions of base pairs of DNA, causes frame-shift mutation.

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Reason: A classical example of frame-shift mutation is sickle cell anaemia.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

7 ➤ 201. Assertion: Increase in a whole set of chromosome in an organism is known as polyploidy.

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Reason: Failure of cytokinesis after telophase stage of cell division results in polyploidy.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

8 ➤ 202. Assertion: Test cross is a back cross. Reason: In test cross, F1 - individual is crossed with recessive parents.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

9 ➤ 203. Assertion: Inheritance of holandric gene are always from father to son. Reason: Holandric genes are found on Y-chromosomes.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

10 ➤ 204. Assertion: In humans, the gamete contributed by the male determines whether the child produced will be male or female.

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Reason: Sex in human is a polygenic trait depending upon a cumulative effect of some gene on X-chromosomes and some on Y-chromosomes.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

11 ➤ 205. Assertion: In birds, the chromosome composition of the sperm determines the sex.

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Reason: Male birds are heterogametic.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

12 ➤ 206. Assertion: Down’s syndrome is chromosomal disorder

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Reason: It occurs due to trisomy of 21 chromosome.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

13 ➤ 207. Assertion: Female of Turner’s syndrome is sterile.

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Reason: Such female contain rudimentary ovaries.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

14 ➤ 208. Assertion: PKU leads to mental retardation

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Reason: Phenylpyruvic acid and their derivatives are accumulated in brain in PKU.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

15 ➤ 209. Assertion: Sickle cell anaemia is an example of point mutation.

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Reason: It occur due change in single nucleotide in beta gene.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

16 ➤ 210. Assertion: Cystic fibrosis is Mendelian disorder .

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Reason: Tuners syndrome is chromosomal disorder.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

17 ➤ 211. Assertion: Haemophilia is commonly found in males.

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Reason: Haemophilia is X- linked recessive disorder.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

18 ➤ 212. Assertion: UV radiation is mutagen.

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Reason: UV radiation can cause mutation in organism.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

19 ➤ 213. Assertion: Genetic make up of sperm determines the sex of human child.

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Reason: Males are homogametic in humans.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

20 ➤ 214. Assertion: Starch grain size is controlled by gene B in pea seed is an example of incomplete dominance.

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Reason: Starch grain formed by genetic constitution Bb is of intermediate size.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false

21 ➤ 1. Study the pedigree chart of a certain family given in figure and select the correct conclusion which can be drawn for the character. [AIPMT MAINS 2010]

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(a) The female parent is heterozygous. (b) The parents could not have had a normal daughter for this character. (c) The trait under study could not be colour blindness. (d) The male parent is homozygous dominant.

22 ➤ 2. In Antirrhinum, two plants with pink flowers were hybridized. The F1 plants produced red, pink and white flowers in the proportion of 1 red, 2 pink and 1 white. What could be the genotype of the two plants used for hybridization of Red flower colour is determined by RR, and white by rr genes? [AIPMT MAINS 2010]

(a) rrrr (b) RR (c) Rr (d) rr

23 ➤ 3. A cross in which an organism showing a dominant phenotype is crossed with the recessive parent in order to know its genotype is called [AIPMT MAINS 2010]

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

24 ➤ 4. ABO blood grouping is controlled by gene I which has three alleles and show co-dominance. There are six genotypes. How many phenotypes in all are possible? [AIPMT MAINS 2010]

(a) Six (b) Three (c) Four (d) Five

25 ➤ 5. The fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of chromosomal theory of inheritance by Morgan and his colleagues because [AIPMT MAINS 2010]

(a) It reproduces parthenogenetically. (b) A single mating produces two young flies. (c) Smaller female is easily recognisable from larger male. (d) It completes the life cycle in about two weeks.

26 ➤ 6. Which one of the following cannot be explained on the basis of Mendel’s Law of Dominance? [AIPMT PRE 2010]

(a) The discrete unit controlling a particular character is called a factor. (b) Out of one pair of factors one is dominant and the other recessive. (c) Alleles do not show any blending and both the characters recover as such in F2 generation. (d) Factors occur in pairs.

27 ➤ 7. The genotype of a plant showing the dominant phenotype can be determined by [AIPMT PRE 2010]

(a) Test cross (b) Dihybrid cross (c) Pedigree analysis (d) Back cross

28 ➤ 8. ABO blood groups in humans are controlled by the gene I. It has three alleles - lA, IB and i. Since there are three different alleles, six different genotypes are possible. How many phenotypes can occur? [AIPMT PRE 2010]

(a) Three (b) One (c) Four (d) Two

29 ➤ 9. Select the correct statement from the ones given below with respect to dihybrid cross. [AIPMT PRE 2010]

(a) Tightly linked genes on the same chromosome show higher recombinations. (b) Genes far apart on the same chromosome shows very few recombinations. (c) Genes loosely linked on the same chromosome show similar recombinations as the tightly linked ones. (d) Tightly linked genes on the same chromosome show very few recombinations.

30 ➤ 10. Which one of the following symbols and its representation, used in human pedigree analysis is correct? [AIPMT PRE 2010]

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(a) (b) (c) (d)

31 ➤ 11. Which one of the following conditions correctly describes the manner of determining the sex in the given example? [AIPMT PRE 2011]

(a) XO type of sex chromosomes determine male sex in grasshopper. (b) XO condition in humans as found in Turner syndrome, determines female sex. (c) Homozygous sex chromosomes (XX) produce male in Drosophila. (d) Homozygous sex chromosomes (ZZ) determine female sex in birds.

32 ➤ 12. A collection of plants and seeds, having diverse alleles of all the genes of a crop is called [AIPMT PRE 2011]

(a) Germplasm (b) Gene library (c) Genome (d) Herbarium

33 ➤ 13. When two unrelated individuals or lines are crossed, the performance of F1 hybrid is often superior to both its parents. This phenomenon is called [AIPMT PRE 2011]

(a) Transformation (b) Splicing (c) Metamorphosis (d) Heterosis

34 ➤ 14. Test cross in plants or in Drosophila involves crossing [AIPMT MAINS 2011]

(a) Between two genotypes with recessive trait (b) Between two F1 hybrids (c) The F1 hybrid with a double recessive genotype (d) Between two genotype with dominant trait

35 ➤ 15. Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female child? [AIPMT MAINS 2011]

(a) Two X chromosomes (b) Only one Y chromosome (c) Only one X chromosome (d) One X and one Y chromosome

36 ➤ 16. Read the following four statements (A to D): [AIPMT MAINS 2012]

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(A) In transcription, adenosine pairs with uracil.

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(B) Regulation of lac operon by repressor is referred to as positive regulation.

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(C) The human genome has approximately 50,000 genes.

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(D) Haemophilia is a sex-linked recessive disease.

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How many of the above statements are right?

(a) 3 (b) 4 (c) 1 (d) 2

37 ➤ 17. A test cross is carried out to [AIPMT MAINS 2012]

(a) Predict whether two traits are linked. (b) Assess the number of alleles of a gene. (c) Determine whether two species or varieties will breed successfully. (d) Determine the genotype of a plant at F2.

38 ➤ 18. Represented below is the inheritance pattern of the certain type of traits in humans. Which one of the following conditions could be an example of this pattern? [AIPMT MAINS 2012]

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(a) Sickel cell anaemia (b) Haemophilia (c) Thalassemia (d) Phenylketonuria

39 ➤ 19. A normal-visioned man whose father was colour blind, marries a women whose father was also colour blind. They have their first child as a daughter. What are the chances that this child would be colour blind? [AIPMT PRE 2012]

(a) 100% (b) 0% (c) 25% (d) 50%

40 ➤ 20. F2 generation in a Mendelian cross showed that both genotypic and phenotypic rations are same as 1 : 2 : 1. It represents a case of [AIPMT PRE 2012]

(a) Co-dominance (b) Dihybrid cross (c) Monohybrid cross with complete dominance (d) Monohybrid cross with incomplete dominance

41 ➤ 21. Which of the following statements is not true of two genes that shows 50 per cent recombination frequency? [AIPMT 2013]

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

42 ➤ 22. Variation in gene frequencies within populations can occur by change rather than by natural selection. This is referred to as [AIPMT 2013]

(a) Genetic flow (b) Genetic drift (c) Random mating (d) Genetic load

43 ➤ 23. 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 the presence of both ‘A’ and ‘B’ type proteins in ‘AB’ blood group individuals. This is an example of [AIPMT 2013]

(a) Codominance (b) Incomplete dominance (c) Partial dominance (d) Complete dominance

44 ➤ 24. Which Mendelian idea is depicted by a cross in which the F1 generation resembles both the parents? [AIPMT 2013]

(a) Incomplete dominance (b) Law of dominance (c) Inheritance of one gene (d) Codominance

45 ➤ 25. The incorrect statement with regard to haemophilia is [AIPMT 2013]

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

46 ➤ 26. If both parents are carriers for thalessemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child? [AIPMT 2013]

(a) No chance (b) 50% (c) 25% (d) 100%

47 ➤ 27. Fruit colour in squash is an example of [AIPMT 2014]

(a) Recessive epistasis (b) Dominant epistasis (c) Complementary genes (d) Inhibitory genes

48 ➤ 28. 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? [AIPMT 2014]

(a) 25% (b) 0% (c) 50% (d) 75%

49 ➤ 29. In a population of 1000 individuals 360 belong to genotype AA, 480 to Aa and the remaining 160 to aa. Based on this data, the frequency of allele A in the population is [AIPMT 2014]

(a) 0.4 (b) 0.5 (c) 0.6 (d) 0.7

50 ➤ 30. A human female with Turner’s syndrome [AIPMT 2014]

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

51 ➤ 31. How many pairs by contrasting characters in pea plants was studied by Mendel in his experiments? [AIPMT 2015]

(a) 5 (b) 6 (c) 8 (d) 7

52 ➤ 32. The movement of a gene from one linkage group to another is called [AIPMT 2015]

(a) Inversion (b) Duplication (c) Translocation (d) Crossing over

53 ➤ 33. Multiple alleles are present [AIPMT 2015]

(a) On different chromosomes (b) At different location in the same chromosome (c) At the same locus of the chromosome (d) On non-sister chromatids

54 ➤ 34. An abnormal human baby with ‘XXX’ sex chromosomes was born due to [AIPMT 2015]

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

55 ➤ 35. Alleles are: [AIPMT 2015]

(a) Different phenotype (b) True breeding homozygotes (c) Different molecular forms of a gene (d) Heterozygotes

56 ➤ 36. A man with blood group ‘A’ marries a woman with blood group ‘B’. which are all the possible blood groups of their offsprings? [AIPMT 2015]

(a) A and B only (b) A, B and AB only (c) A, B, AB and O (d) O only

57 ➤ 37. In his classic experiments on pea plants, Mendel did not use. [RE-AIPMT 2015]

(a) Pod length (b) Seed shape (c) Flower position (d) Seed colour

58 ➤ 38. A pleiotropic gene: [RE-AIPMT 2015]

(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

59 ➤ 39. A gene showing codominance has: [RE-AIPMT 2015]

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

60 ➤ 40. 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? [RE-AIPMT 2015]

(a) 1 (b) Nil (c) 0.25 (d) 0.5

61 ➤ 41. The term “linkage” was coined by: [RE-AIPMT 2015]

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

62 ➤ 42. In the following human pedigree, the filled symbols represent the affected individual. Identify the type of given pedigree.

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(a) X-linked recessive (b) Autosomal recessive (c) X-linked dominant (d) Autosomal dominant

63 ➤ 43. Which of the following most appropriately describes haemophilia? [NEET - I, 2016]

(a) Recessive gene disorder (b) X–linked recessive gene disorder (c) Chromosomal disorder (d) Dominant gene disorder

64 ➤ 44. 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: [NEET - I, 2016]

(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

65 ➤ 45. Match the terms in Column I with their description in Column II [NEET - I, 2016]

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(a) Dominance - (i) Many genes govern a single character

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(b) Codominance - (ii) In a heterozygous organism only one allele expresses itself.

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(c) Pleiotropy - (iii) In a heterozygous organisms both alleles express themselves fully

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(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

66 ➤ 46. Pick out the correct statements: [NEET - I, 2016]

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(A) Haemophilia is a sex-linked recessive disease.

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(B) Down’s syndrome is due to aneuploiday.

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(C) Phenyllketonuria is an autosomal recessive gene disorder.

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(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

67 ➤ 47. The amino acid Tryptophan is the precursor for the synthesis of: [NEET - I, 2016]

(a) Melatonin and Serotonin (b) Thyroxine and Triiodothyronine (c) Estrogen and Progesterone (d) Cortisol and Cortisone

68 ➤ 48. In a testcross involving F1 dihybrid flies, more parental-type offspring were produced the recombinant-type offspring. This indicates: [NEET - I, 2016]

(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

69 ➤ 49. A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other, dividing cells. This would result in: [NEET - I, 2016]

(a) Aneuploidy (b) Polyploidy (c) Somaclonal variation (d) Polyteny

70 ➤ 50. Taylor conducted the experiments to prove semi conservative mode of chromosome replication on [NEET - II, 2016]

(a) Vicia faba (b) Drosophila melanogaster (c) E. coli (d) Vinca rosea

71 ➤ 51. The mechanism that causes a gene o move from the linkage group to another is called. [NEET - II, 2016]

(a) Duplication (b) Translocation (c) Crossing over (d) Inversion

72 ➤ 52. A true breeding plant is [NEET - II, 2016]

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

73 ➤ 53. If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is [NEET - II, 2016]

(a) 0.5 (b) 0.75 (c) 1 (d) 0

74 ➤ 1. All genes are located on the same chromosome

(a) Form different groups depending upon their relative distance. (b) Form one linkage group. (c) Will not form any linkage groups. (d) Form interactive groups that affect the phenotype.

75 ➤ 2. Conditions of a karyotype 2n ± 1 and 2n ± 2 are called

(a) Aneuploidy (b) Polyploidy (c) Allopolyploidy (d) Monosomy

76 ➤ 3. Distance between the genes and percentage of recombination shows

(a) A direct relationship (b) An inverse relationship (c) A parallel relationship (d) No relationship

77 ➤ 4. If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, then the disease is

(a) Autosomal dominant (b) Autosomal recessive (c) Sex-linked dominant (d) Sex-linked recessive

78 ➤ 5. In sickle cell anaemia, the glutamic acid is replaced by valine. Which one of the following are triplet codes for valine?

(a) G G G (b) A A G (c) G A A (d) G U G

79 ➤ 6. A person having genotype IA IB would show the blood group as AB. This is because of

(a) Pleiotropy (b) Co-dominance (c) Segregation (d) Incomplete dominance

80 ➤ 7. ZZ/ZW type of sex determination is seen in

(a) Platypus (b) Snails (c) Cockroach (d) Peacock

81 ➤ 8. A cross between two tall plants resulted in an offspring having few dwarf plants. What would be the genotypes of both the parents?

(a) TT and Tt (b) Tt and Tt (c) TT and TT (d) Tt and tt

82 ➤ 9. In a dihybrid cross, if you get 9 : 3 : 3 : 1 ratio, it denotes that

(a) The alleles of two genes are interacting with each other. (b) It is a multigenic inheritance. (c) It is a case of multiple allelism. (d) The alleles of two genes are segregating independently.

83 ➤ 10. Which of the following will not result in variations among siblings?

(a) Independent assortment of genes (b) Crossing over (c) Linkage (d) Mutation

84 ➤ 11. Mendel’s Law of independent assortment holds good for genes situated on the

(a) Non-homologous chromosomes (b) Homologous chromosomes (c) Extra nuclear genetic element (d) Same chromosome

85 ➤ 12. Occasionally, a single gene may express more than one effect. This phenomenon is called

(a) Multiple allelism (b) Mosaicism (c) Pleiotropy (d) Polygeny

86 ➤ 13. In a certain taxon of insects, some have 17 chromosomes and the others have 18 chromosomes. The 17 and 18 chromosome-bearing organisms are

(a) Males and females, respectively (b) Females and males, respectively (c) All males (d) All females

87 ➤ 14. The inheritance pattern of a gene over generations among humans is studied by the pedigree analysis. Character studied in the pedigree analysis is equivalent to

(a) Quantitative trait (b) Mendelian trait (c) Polygenic trait (d) Maternal trait

88 ➤ 15. It is said that Mendel proposed that the factor controlling any character is discrete and independent. His proposition was based on the

(a) Results of F3 generation of a cross. (b) Observations that the offspring of a cross made between the plants having two contrasting characters show only one character without any blending. (c) Self-pollination of F1 offsprings. (d) Cross pollination of F1 generations with recessive parental.

89 ➤ 16. Two genes ‘A’ and ‘B’ are linked. In a dihybrid cross involving these two genes, the F1 heterozygote is crossed with homozygous’ recessive parental type (aa bb). What would be the ratio of offspring in the next generation?

(a) 1 : 1 : 1 : 1 (b) 9 : 3 : 3 : 1 (c) 3 : 1 (d) 1 : 1

90 ➤ 17. In the F2 generation of a Mendelian dihybrid cross, the number of phenotypes and genotypes are

(a) Phenotypes-4; genotypes-16 (b) Phenotypes-9; genotypes-4 (c) Phenotypes-4; genotypes-8 (d) Phenotypes-4; genotypes-9

91 ➤ 18. Mother and father of a person with ‘O’ blood group have ‘A’ and ‘B’ blood group respectively. What would be the genotype of both mother and father?

(a) Mother is homozygous for ‘A’ blood group and the father is heterozygous for ‘B’. (b) Mother is heterozygous for ‘A’ blood group and the father is homozygous for ‘B’. (c) Both mother and father are heterozygous for ‘A’ and ‘B’ blood group, respectively. (d) Both mother and father are homozygous for ‘A’ and ‘B’ blood group, respectively

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