LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION - BIOTECHNOLOGY
FIRST SEMESTER – NOVEMBER 2010
BT 1819 - MICROBIAL PHYSIOLOGY & GENETICS
Date : 30-10-10
Time : 1:00 - 4:00
Dept. No.
Max. : 100 Marks
Section A
Answer all questions
I Choose the correct answer
(20marks)
(5 x 1 = 5)
1. Match: A) Ribosome B) Mesosome C) Carboxysome D) Episome
with i) CO2 fixation ii) Svedberg unit iii) plasmid iv) cell division
a) A-iv, B-iii, C-ii, D-i
b) A-ii, B-iv, C-iii, D-i
c) A-iii, B-i, C-iv, D-ii
d) A-ii, B-iv, C-I, D-iii
2. Plasmid consists of tra and trb locus which are made up of _____________.
a) 33Kb & 40genes b) 34Kb & 41genes
c) 35Kb & 42genes
d) 36Kb & 43genes
3. The products of recB and recC genes are known as ____________.
a) RecBCE
b) RecBCD
c) RecABC
d) RecBCF
4. ____________ protein is responsible for removing the mismatched strand.
a) MutL
b) MutS
c) MutH
d) MutU
5. StatementA: Nitrosomonas is a free living N2 fixing bacteria
StatementB: It coverts ammonia to nitrite.
a) Statement A is correct, Statement B is incorrect
b) Statement B is correct, Statement A is incorrect
c) Both A and B are correct
d) Both A and B are incorrect
II State whether the following are True or False. If False, give reasons
(5 x 1 = 5)
6. Neisseria is a gram positive, monotrichous, diplococcus bacterium.
7. Organisms obtaining energy from external chemical compounds are heterotrophic.
8. HML is the abbreviation for High Mat Line.
9. Ethylene ethyl sulfonate is used as an intercalating agent.
10. Faecal contamination is mainly due to Coliform.
.
III Complete the following
(5 x 1 = 5)
11. The two sugar derivatives of the peptidoglycan polymer are ________ and __________.
12. The phase in which death and growth are balanced is called as ____________.
13. _____________ is deleted to make space for foreign DNA to enter a replacement vector.
14. Hugo de Vries worked on ____________ to describe the phenotypic changes.
15. Exotoxins are heat ______________ and are mainly made up of ___________ bacteria.
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IV Answer in one or two sentences, each in about 50 words
(5 x 1 = 5)
16. What are fimbriae? Mention their functions.
17. Define sulphur bacteria.
18. What are Rec mutants?
19. What do you mean by the term reversion?
20. Mention the causal organism and morphology of Cholera organism.
Section B
V Answer the following, each answer within 500 words; draw diagrams wherever
necessary
(5 x 7 = 35)
21. (a) Describe the ultra structure of gram positive cell wall. How does it differ from gram
negative cell wall (any 4 differences)?
OR
(b) Discuss the importance of radiation as a physical method of microbial control.
22. (a) Mention the role of chlorophyll and carotenoids during microbial metabolism.
OR
(b) Briefly explain nitrogen fixation.
23. (a) Explain genetic recombination and the role of Rec genes in phage replication.
OR
(b) What vital role does Neurospora play in order to study its genetic systems.
24. (a) Give a brief explanation on spontaneous mutation.
OR
(b) Explain suppression in mutants and list the class of chemicals along with their chemical
mutagens.
25. (a) Write about any five methods of food preservation.
OR
(b) Discuss the factors which influence infection of microbes.
Section C
VI Answer any THREE of the following, each within 1200 words; draw diagrams wherever
necessary
(3 x 15 = 45)
26. Describe the structures internal to the cell wall of a bacterium.
27. Explain the nature of microbial growth and the various growth phases.
28. Explain the different types of transduction.
29. Define DNA damage. Explain the causes and its repair mechanism.
30. Write notes on:
a) Carbon cycle
b) Any five physical factors in aquatic microbiology
c) Endotoxins
(3 x 5 = 15)
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