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12th Standard Biology English Medium Classical Genetics Reduced Syllabus Important Questions With Answer Key 2021

12th Standard

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Biology

Time : 01:00:00 Hrs
Total Marks : 100

    Multiple Choice Questions

    15 x 1 = 15
  1. Extra nuclear inheritance is a consequence of presence of genes in _____.

    (a)

    Mitrochondria and chloroplasts

    (b)

    Endoplasmic reticulum and mitrochondria

    (c)

    Ribosomes and chloroplast

    (d)

    Lysososmes and ribosomes

  2. The genotype of a plant showing the dominant phenotype can be determined by _____.

    (a)

    Back cross

    (b)

    Test cross

    (c)

    Dihybrid corss

    (d)

    Pedigree analysis

  3. The epistatic effect, in which the dihybrid cross 9:3:3:1 between AaBb Aabb is modified as ______.

    (a)

    Dominance of one allele on another allele of both loci

    (b)

    Interaction between two alleles of different loci

    (c)

    Dominance of one allele to another alleles of same loci

    (d)

    Interaction between two alleles of some loci

  4. In a test cross involving F1 dihybrid flies, more parental type offspring were produced than the recombination type offspring. This indicates ______.

    (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 some chromosome

    (d)

    Both of the characters are controlled by more than one gene

  5. The genes controlling the seven pea characters studied by Mendel are known to be located on how many different chromosomes?

    (a)

    Seven

    (b)

    Six

    (c)

    Five

    (d)

    Four

  6. “Gametes are never hybrid”. This is a statement of ______.

    (a)

    Law of dominance

    (b)

    Law of independent assortment

    (c)

    Law of segregation

    (d)

    Law of random fertilization

  7. The term 'Genetics' was introduced by__________

    (a)

    Gregor Mendel

    (b)

    W. Bateson

    (c)

    Hugo de Vries

    (d)

    Carl Correns

  8. How many characters studied by Mendel in pisum sativum

    (a)

    Three

    (b)

    Five

    (c)

    Seven

    (d)

    Nine

  9. Assertion (A): Codominance is an example of intragenic interaction
    Reason (R): Interaction takes place between the alleles of the same gene

    (a)

    A and R are correct R explains A

    (b)

    A and R are incorrect

    (c)

    A is correct R is incorrect

    (d)

    A is incorrect R is correct

  10. Identify the mismatched pair

    (a)

    Chloroplast inheritance - Gregor Mendel

    (b)

    Polygenic inheritance - H. Nilsson

    (c)

    Lethal genes - E. Baur

    (d)

    Incomplete dominance - Carl Correns

  11. Statement 1: Test cross is done between F1 individual with homozygous recessive
    Statement 2: If F 1 individual is homozygous, the rate of a monohybrid cross will be 1:1

    (a)

    Statement 1 is correct & Statement 2 is incorrect

    (b)

    Statement 1 is incorrect & Statement 2 is correct

    (c)

    Both Statements 1 & 2 are correct

    (d)

    Both Statements 1 & 2 are incorrect

  12. How many genetically different gametes are produced by a plant have genotype TtYyRr?

    (a)

    2

    (b)

    4

    (c)

    6

    (d)

    8

  13. According to Mendel, which is not a dominant trait?

    (a)

    Wrinkled seeds

    (b)

    Purple flower

    (c)

    Inflated pod form

    (d)

    Axial flower portion

  14. Factor hypothesis was proposed by _________

    (a)

    Reginald Punnett

    (b)

    W. Bateson

    (c)

    Gregor Mendel

    (d)

    Carl Correns

  15. The 1 : 2 : 1 ratio of co-dominance process Mendel's ___________

    (a)

    Law of dominance

    (b)

    Law of recessiveness

    (c)

    Law of segregation

    (d)

    Law of independent assortment

  16. 2 Marks

    10 x 2 = 20
  17. What is meant by true breeding or pure breeding lines / strain?

  18. Give the names of the scientists who rediscovered Mendelism

  19. Define Genetics.

  20. Name the four major subdisciplines of genetics.

  21. Define the terms
    (i) Emasculation
    (ii) Alleles

  22. Name the first and second law of Mendel.

  23. How many types of gametes are produced by a dihybrid plant? If the same plant is self-fertilized, how many second-generation offsprings are developed?

  24. Provide any four intergenic gene interactions.

  25. Define lethal alleles.

  26. What are plasmogenes?

  27. 3 Marks

    10 x 3 = 30
  28. What are multiple alleles?

  29. Explain the law of dominance in monohybrid cross.

  30. Differentiate incomplete dominance and codominance.

  31. What is meant by cytoplasmic inheritance

  32. List out the reasons for the selection of pea plant by Mendel.

  33. State the law of segregation.

  34. Define trihybrid cross. Mention its F 2 phenotypic ratio.

  35. Define co-dominance. How it is proved by using Gossypium species?

  36. Give an account on cytoplasmic male sterility.

  37. Write a short notes on Atavism.

  38. 5 Marks

    7 x 5 = 35
  39. Describe dominant epistasis with an example. 

  40. Explain polygenic inheritance with an example.

  41. Differentiate continuous variation with discontinuous variation.

  42. Explain with an example how single genes affect multiple traits and alleles the phenotype of an organism.

  43. Bring out the inheritance of chloroplast gene with an example.

  44. How does the wrinkled gene make Mendel's peas wrinkled? Find out the molecular explanation.

  45. Describe incomplete dominance exhibited by Mirabilis jalapa.

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