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12th Standard Biology English Medium Reduced Syllabus Important Questions with Answer key - 2021 Part - 2

12th Standard

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Biology

Time : 02:45:00 Hrs
Total Marks : 165

    Multiple Choice Questions

    15 x 1 = 15
  1. In which type of parthenogenesis are only males produced?

    (a)

    Arrhenotoky

    (b)

    Thelytoky

    (c)

    Amphitoky

    (d)

    Both a and b

  2. The site of embryo implantation is the

    (a)

    Uterus

    (b)

    Peritoneal cavity

    (c)

    Vagina

    (d)

    Fallopian tube

  3. Which of the following is correct regarding HIV, hepatitis B, gonorrhoea and trichomoniasis?

    (a)

    Gonorrhoea is a STD whereas others are not.

    (b)

    Trichomoniasis is a viral disease whereas others are bacterial.

    (c)

    HIV is a pathogen whereas others are diseases.

    (d)

    Hepatitis B is eradicated completely whereas others are not.

  4. If the childs blood group is ‘O’ and fathers blood group is ‘A’ and mother’s blood group is ‘B’ the genotype of the parents will be

    (a)

    IA IA and IB Io

    (b)

    IA Io and IB Io

    (c)

    IA Io and IoIo

    (d)

    IoIo and IB IB

  5. Which of the following is incorrect regarding ZW-ZZ type of sex determination?

    (a)

    It occurs in birds and some reptiles

    (b)

    Females are homogametic and males are heterogametic

    (c)

    Male produce two types of gametes

    (d)

    It occurs in gypsy moth

  6. An operon is a:

    (a)

    Protein that suppresses gene expression

    (b)

    Protein that accelerates gene expression

    (c)

    Cluster of structural genes with related function

    (d)

    Gene that switched other genes on or off

  7. Darwin’s finches are an excellent example of

    (a)

    connecting links

    (b)

    seasonal migration

    (c)

    adaptive radiation

    (d)

    parasitism

  8. Spread of cancerous cells to distant sites is termed as

    (a)

    Metastasis

    (b)

    Oncogenes

    (c)

    Proto-oncogenes

    (d)

    Malignant neoplasm

  9. Vaccines that use components of a pathogenic organism rather than the whole organism are called

    (a)

    Subunit recombinant vaccines

    (b)

    attenuated recombinant vaccines

    (c)

    DNA vaccines

    (d)

    conventional vaccines

  10. Which of the following is correct for r-selected species

    (a)

    Large number of progeny with small size

    (b)

    large number of progeny with large size

    (c)

    small number of progeny with small size

    (d)

    small number of progeny with large size

  11. Which among the following always decreases in a Food chain across tropic levels?

    (a)

    Number

    (b)

    Accumulated chemicals

    (c)

    Energy

    (d)

    Force

  12. SMOG is derived from :

    (a)

    Smoke

    (b)

    Fog

    (c)

    Both A and B

    (d)

    Only A

  13. Test cross involves

    (a)

    Crossing between two genotypes with recessive trait

    (b)

    Crossing between two F1 hybrids

    (c)

    Crossing the F1 hybrid with a double recessive genotype

    (d)

    Crossing between two genotypes with dominant trait

  14. The A and B genes are 10 cM apart on a chromosome. If an AB/ab heterozygote is testcrossed to ab/ab, how many of each progeny class would you expect out of 100 total progeny?

    (a)

    25 AB, 25 ab, 25 Ab, 25 aB

    (b)

    10 AB, 10 ab

    (c)

    45 AB, 45 ab

    (d)

    45 AB, 45 ab, 5 Ab, 5aB

  15. Match list I with list II
     

    List I list II
    A. A pair of chromosomes extra with diploid i) monosomy
    B. One chromosome extra to the diploid ii) tetrasomy
    C. One chromosome loses from diploid iii) trisomy
    D.Two individual chromosomes lose from diploid

    iv) double monosomy

    (a)

    A-i, B-iii, C-ii, D-iv

    (b)

    A-ii, B-iii, C-iv, D-i

    (c)

    A-ii, B-iii, C-i, D-iv

    (d)

    A-iii, B-ii, C-i, D-iv

  16. 2 Marks

    15 x 2 = 30
  17. Name the phenomenon where the female gamete directly develops into a new organism with with an avian example

  18. Draw a labeled sketch of a spermatozoan.

  19. What is criss-cross inheritance?

  20. What is biological oxygen demand?

  21. Explain how “Rosie” is different from a normal cow

  22. Differentiate between Eurytherms and Stenotherms.

  23. Name the active chemical found in the medicinal plant Rauwolfia vomitoria. What type of diversity it belongs to?

  24. List all the wastes that you generate, at home, school or during your trips to other places. Could you very easily reduce the generation of these wastes? Which would be difficult or rather impossible to reduce?

  25. A detached leaf of Bryophyllum produces new plants. How?

  26. “Tissue culture is the best method for propagating rare and endangered plant species”- Discuss.

  27. If you cross dominant genotype PV/PV male Drosophila with double recessive female and obtain F1 hybrid. Now you cross F1 male with double recessive female.
    i) What type of linkage is seen?
    ii) Draw the cross with correct genotype.
    iii) What is the possible genotype in F2 generation?

  28. What is the difference between missense and nonsense mutation?

  29. Write the various steps involved in cell suspension culture.

  30. Soil formation can be initiated by biological organisms. Explain how?

  31. How are microbial innoculants used to increase the soil fertility?

  32. 3 Marks

    15 x 3 = 45
  33. What is apolysis? Write its significance.

  34. Mention the importance of the position of the testes in humans.

  35. Define gametogenesis.

  36. What is Relaxin?

  37. How is sex determined in human beings?

  38. Brief about female heterogamety

  39. From their examination of the structure of DNA, What did Watson and Crick infer about the probable mechanism of DNA replication, coding capability and mutation?

  40. Who disproved Lamarck’s Theory of acquired characters? How?

  41. What is vaccine? What are its types?

  42. What are stem cells? Explain its role in the field of medicine

  43. What are called endangered species? Explain with examples

  44. What is polyembryony. How it can commercially exploited.

  45. Explain the mechanism of crossing over.

  46. Shape of pyramid in a particular ecosystem is always different in shape. Explain with example.

  47. Which one gas is most abundant out of the four commonest greenhouse gases? Discuss the effect of this gas on the growth of plants?

  48. 5 Marks

    15 x 5 = 75
  49. Given an account on following terms.
    (a) Hologamy
    (b) Isogamy
    (c) Anisogamy
    (d) Merogamy
    (e) Paedogamy

  50. Describe the structure of HIV with a diagram

  51. Write a note on gene banks

  52. What is the impact of agrochemicals on the living organisms?

  53. How agrochemicals affect ecosystem?

  54. Explain the development process of male gametophyte.

  55. Describe the structure of a dicot seed.

  56. Describe the steps involved in recombinant DNA technology.

  57. Write a note on Replica plating technique.

  58. Point out the applications of plant tissue culture.

  59. What are the strategies of eco system management?

  60. Write in detail about Autogenic succession and Allogenic succession.

  61. Give an account of active principle and medicinal values of any two plants you have studied.

  62. Give a detailed account on anyone fibe yielding plant.

  63. Explain the stepwise preparation of Bio-pest repellent from the leaves of Azadirachta indica

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