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12th Standard Biology English Medium Classical Genetics Reduced Syllabus Important Questions 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. Which one of the following is an example of polygenic inheritance?

    (a)

    Flower colour in Mirabilis Jalapa

    (b)

    Production of male honey bee

    (c)

    Pod shape in garden pea

    (d)

    Skin Colour in humans

  3. The genotype of a plant showing the dominant phenotype can be determined

    (a)

    Back cross

    (b)

    Test cross

    (c)

    Dihybrid corss

    (d)

    Pedigree analysis

  4. Fruit colour in squash is an example of

    (a)

    Recessive epistatsis

    (b)

    Dominant epistasis

    (c)

    Complementary genes

    (d)

    Inhibitory genes

  5. Gene which suppresses other genes activity but does not lie on the same locus is called as

    (a)

    Epistatic

    (b)

    Supplement only

    (c)

    Hypostatic

    (d)

    Codominant

  6. Pure tall plants are crossed with pure dwarf plants. In the F1 generation, all plants were tall. These tall plants of F1 generation were selfed and the ratio of tall to dwarf plants obtained was 3:1. This is called

    (a)

    Dominance

    (b)

    Inheritance

    (c)

    Codominance

    (d)

    Heredity

  7. Which is not a correct statement?
    (A) Variations are the raw materials for evolution
    (B) Variations provide genetic material for natural selection
    (C) It helps the individual to adapt to the changing environment
    (D) Variations allow breeders to improve the crop field

    (a)

    A and D

    (b)

    B only

    (c)

    C and D

    (d)

    none of he above

  8. Assertion (A): Test cross is done between F2 hybrid with F. recessive
    Reason (R): It helps to identify the homozygosity of hybrids

    (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

  9. Identify the mismatched pair

    (a)

    Chloroplast inheritance - Gregor Mendel

    (b)

    Polygenic inheritance - H. Nilsson

    (c)

    Lethal genes - E. Baur

    (d)

    Incomplete dominance - Carl Correns

  10. 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

  11. Identify the incorrect statement

    (a)

    In incomplete dominance, the traits are blended not the genes

    (b)

    Incomplete dominance is noticed in Mirabilis jalapa by Carl Correns

    (c)

    It is a type of Intragenic gene interaction

    (d)

    Incomplete dominance F2 ratio is 1 : 3 : 1

  12. When a single gene influences multiple traits then the phenomenon is called ____________

    (a)

    Pleiotropy

    (b)

    Polygenic inheritance

    (c)

    Epistasis

    (d)

    Atavism

  13. Ratio of recessive epistasis is ___________

    (a)

    12: 3 : 1

    (b)

    9: 7

    (c)

    9: 3 : 4

    (d)

    9: 6 : 1

  14. 'Gametes are never hybrid' is concluded by ___________

    (a)

    Law of dominance

    (b)

    Law of segregation

    (c)

    Law of independent environment

    (d)

    Law of lethality

  15. Factor hypothesis was proposed by _________

    (a)

    Reginald Punnett

    (b)

    W. Bateson

    (c)

    Gregor Mendel

    (d)

    Carl Correns

  16. 2 Marks

    10 x 2 = 20
  17. Define Heredity and variations

  18. Write the phenotypic and genotypic ratio of monohybrid cross.

  19. State the law of independent assortment.

  20. 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?

  21. Classify gene interactions with an example.

  22. Define intragenic interaction

  23. What are lethal alleles? Give example.

  24. What is intergenic gene interactions? Give example

  25. What are plasmogenes?

  26. What is cytoplasmic male sterility?

  27. 3 Marks

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

  29. What are the reasons for Mendel’s successes in his breeding experiment?

  30. Explain the law of dominance in monohybrid cross.

  31. Differentiate incomplete dominance and codominance.

  32. Point out any three importance of variations.

  33. How many types of gametes are produced by heterozygous dihybrid plant with a genotype RrYy? Write them.

  34. Write a short note on Atavism.

  35. In the chart given below, 'AA' are the genes located in a chromosome of Pisum sativum.
    Observe the chart and mention the genetic phenomenon does it indicates.

  36. Give the F2 phenotypic ratio of
    a) Supplementary genes
    b) Complementary genes
    c) Dominant epistasis

  37. Name the respective pattern of inheritance where F 1phenotype
    a) resembles anyone of the two parents
    b) is an intermediate between two parental traits.

  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. Explain Dihybrid cross in pea plant.

  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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