Tamil Nadu State Board Micro Biology Sample Paper for Class 12

Tamil Nadu Board of Higher Secondary Education Sample Paper / Model Paper for Class 12 Micro Biology is given below.

XII Standard –Microbiology
Model Question Paper

Time : 3 hours
Maximum marks :150

1. Answer all the questions from Part I
2. Answer any fifteen questions from Part II
3. Answer only six questions from Part III
4. Question no. 71 is compulsory
5. Answer only four questions from Part IV
6. Draw diagrams wherever necessary

Part I

Note: Answer all the questions 50 x 1 = 50 marks

A. Choose the correct answer

1. The credit of making a compound microscope goes to
a. Robert Hooke
b. Zaccharias
c. Knoll
d. Zernike

2. TCA cycle is also known as
a. Kreb’ s cycle
b. Citric acid cycle
c. Amphibolic cycle
d. All the above

3. A substance acted upon by an enzyme is called
a. Co factor
b. Co enzyme
c. Substrate
d. Holoenzyme

4. Primary treatment of sewage removes which percentage of BOD?
a. 5-10
b. 15-20
c. 20-25
d. 30-40

5. Which of the following is resistant to decomposition?
a. Cellulose
b. Hemicellulose
c. Fructose
d. Lignin

6. Which of the following is used for the production of wine?
a. Acetic acid bacteria
b. Lactic acid bacteria
c. Propionic acid bacteria
d. Yeasts

7. A zone of complete clearing of blood around the colonies is called:
a. Alpha hemolysis
b. Beta hemolysis
c. Gamma hemolysis
d. All the above

8. Diphtheria toxin acts on which of the following?
a. Nucleic acid synthesis
b. Protein synthesis
c. Lipid synthesis
d. All the above

9. Vibrio cholerae is:
a. Gram negative rod
b. Gram positive rod
c. Gram negative curved rod
d. Gram variable rod

10. Clostridium tetani grows in
a. Presence of oxygen
b. In the absence of oxygen
c. Both in presence and in absence of oxygen
d. Presence of carbon di oxide

11. Leishmania donovani is transmitted by:
a. Ticks
b. Sand fly
c. Mosquitoes
d. Rat flea

12. Candida albicans produces
a. Sporangio spores
b. Capsule
c. Pseudomycelium
d. All the above

13. HIV attaches to the CD4 receptors of
a. T helper cells
b. B cells
c. Platelets
d. RBC

14. In Lyme disease, a red macule or papule that expands to form a large annular
lesion is called:
a. Psoriasis
b. Erythema migrans
c. Migrains
d. Larva migrans

15. Nurse cells are present in which organ?
a. Skin
b. Intestine
c. Liver
d. Thymus

16. Which antibody appears first after primary infection?
a. Ig A
b. Ig M
c. Ig G
d. All the above

17. Type I hypersensitivity is __________mediated
a. Ig E
b. Ig M
c. Ig G
d. Ig A

18. In the indirect immunofluorescence test, which of the following is labeled with flurochrome?
a. Specific antibody to antigen
b. Antibody to immunoglobulin
c. Antigen
d. All the above

19. The genetic code consists of how many codons?
a. 64
b. 32
c. 128
d. 16

20. Which of the following is a stop codon?
a. UGA
b. GCU
c. CAG
d. AAG

Fill in the blanks ( Answer should be a line phrase or a word)

21. __________is a complex and highly advanced microscope

22. The trickling filter is employed for__________treatment

23. Adhesion of streptococcus pyogenes to pharyngeal epithelial cells is mediated by- __________

24. Bacillary dysentery spreads by the __________route

25. T.brucei gambiense is endemic in __________

26. Brucella infection in pregnant animals leads to__________

27. The harmful reaction of immune system is __________

28. The agents that cause mutations are called

C. Say true or False

29. The system of antiseptic surgery was developed by Joseph Lister

30. Bacillus thuringiensis is a bio fertilizer

31. Staphylococci are seen as chain

32. Cholera stool appears like a rice-water

33. Shigellae are gram negative cocci

34. Cryptococcus is a capsulated yeast cell

35. Lyme disease is caused by Borrelia burgdorferi

36. Thymus is located in the abdomen

37. Two types of light immunoglobulin chains are seen

38. Nirenberg-Khorana solved the structure of DNA

D. Match the following

39. Brucella a. Meningitis
40. T.pallidum b. Typhoid fever
41. Edward Jenner c. Travelers diarrhoea
42. Salmonella typhi d. Syphilis
43. Escherichia coli e. Malta fever
44. Cryptococcus f. Vaccine

E. Give answer in one sentence

45. Give two examples of air borne infections

46. Define mutualism

47. Name the toxins produced by Clostridium tetani

48. Give the names of two fungi that cause mycetoma

49. What is cysticercus?

50. What is erythroblastosis faetalis?


Answer any fifteen questions 15×2=30 marks

51. What is tyndalization?

52. Give two uses of fluorescence microscope

53. What are bactericidal agents ? Give examples

54. Define glycolysis

55. Define composting

56. What are the causes of food poisoning?

57. Define antibiotic

58. What is alpha hemolysis? Give examples of organisms producing it

59. State the characteristics of pseudomembrane seen in diphtheria

60. Give the structure of Tetanus bacillus

61. Give the list of diseases produced by Chlamydia trachomatis

62. Describe the structure of Taenia solium

63. Describe the cryptococcal clinical manifestations

64. What are the types of HSV?

65. What is Lyme borreliosis?

66. Define antigen

67. Name two enzymes used in ELISA test

68. What is toxoid ? State its characteristics

69. Define mutation

70. Define phenotype


Answer any six questions. Question number 71 is compulsory 6 x 5 = 30

71. Compare direct and indirect immunofluorescence tests or Describe the pathogenesis of cryptococcosis

72. Write short notes on enzyme regulation by feed back inhibition

73. Write the role of biofertilizers in agriculture

74. What are the clinical features of bacillary dysentery?

75. Describe the clinical features of tetanus

76. Explain the laboratory diagnosis and control of human taeniasis

77. Write notes on food preservation

78. Describe the structure of heavy chain of immunoglobulin molecule with diagram

79. Describe Ti plasmid with diagram


Answer four of the following questions 4 x 10 = 40 marks

80. Discuss in detail the work of Louis Pasteur

81. How will you evaluate antimicrobial action of disinfectant?

82. Write the organisms, raw materials and industrial production of penicillin. What are the different types of penicillins?

83. Describe in detail the prophylaxis of diphtheria

84. Write in detail the structure, function and pathogenesis of cholera toxin

85. Explain in detail the epidemiology, prevention and control of brucellosis

86. Describe the development of T cells in thymus

87. Describe the production of transgenic animals

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