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P.T.O.
MAR IVANIOS COLLEGE (AUTONOMOUS)
THIRUVANANTHAPURAM
Reg. No. :.………………… Name :.………………
First Semester Career Related B.Sc. Degree Examination, November 2017
First Degree Programme under CBCSS Vocational Course (for Botany and Biotechnology)
AUBB151: Microbiology
Time: 3 Hours Max. Marks: 80
SECTION A
Answer ALL the following in a word or one or two sentences.
1. Asepsis.
2. Mycoplasma.
3. Bacteriophage.
4. Auxotroph.
5. Antibiotic.
6. Stationary growth phase.
7. Synthetic media.
8. SCP.
9. The phenomenon by which fungi display the two growth forms viz., yeasts and molds is called
10. Serial dilution.
(10 x 1 10 Marks)
SECTION B
Answer any EIGHT questions, not exceeding a paragraph.
11. In what specific way does ultraviolet light destroy microorganisms
12. Differentiate between halophile and osmophile.
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13. What specific mechanisms are responsible for inactivation of microbes by heavy metals
14. What would be the source of nutrition of chemosynthetic heterotrophs
15. What role does microbial antagonism play in nature
16. What is the importance of nitrogen fixation
17. Explain how turbidometry can be employed to quantitate bacteria in a culture sample.
18. Enumerate reasons why agar is used as a gelling agent in microbial cultures.
19. Give two reasons why it is important to invert petri plates during incubation of bacterial cultures.
20. In what physiological way does penicillin affect penicillin-sensitive bacteria
21. Distinguish between a disinfectant and antibiotic.
22. What is difference between the effect of dipping versus swabbing alcohol as disinfectant. Which method is more effective
x 2 16 Marks)
SECTION C
Short essay type Answer any SIX questions.
23. Give reasons why endospores are much more resistant to heat than are vegetative cells.
24. Why are facultative organisms able to grow with or without oxygen while aerobes grow only in its presence
25. Differentiate lytic and lysogenic bacteriophages.
26. How is replica plating experiment performed for identification of microbial mutants
27. What is the significance of minimum inhibitory concentration How is it determined
28. Define fermentation. What are the two types of fermentation processes
29. What are the various agents used for strain improvement of industrial microbes
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30. Compare and contrast streak plate and pour plate method for separating microbes. Which method is effective for best separation
31. List and describe any four physical methods for microbial control.
x 4 24 Marks)
SECTION D
Long essay type Answer any TWO questions.
32. Explain the mode of action of key classes of antibiotics and mechanism of microbial resistance to these antibiotics.
33. Tabulate the problems associated with heterologous protein production in E. coli and possible solutions to overcome the same. Enumerate the advantages of Bacillus subtilis over E. coli for heterologous protein production.
34. What are single cell proteins (SCPs) Enumerate the advantages and disadvantages of SCPs.
35. Give a brief account of the role of microorganisms in carbon cycle.
x 15 30 Marks)