BSc.-Basic Life Sciences -II: Microbial Techniques-Mumbai-November 2018
MUMBAI UNIVERSITY
Subject: Basic Life Sciences -II: Microbial Techniques
Semester: 1
[Total Time: 2½ hours]
[Total Marks: 75 ]
Note: 1) All questions are compulsory.
2) Each question carries equal marks.
3) Draw diagrams wherever necessary.
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Q.1) Do as directed. (Any 15) (15M)
1) What is decimal reduction time?
2) Give one example of elements used in cultural media.
3) Define- Acid-fast bacteria
4) Explain the term ‘Phototrophs’
5) Define- Mordant
6) Define- Simple Staining
7) Explain the term ‘Pure culture’
8) Define- Compound Microscope
9) __________is a simple and rapid method for measuring growth on the basis of the turbidity of the culture.
10) What is chromogen?
11) Define- Numerical aperture
12) Give one example of Organisms that can reduce inorganic compounds as electron donors.
13) Tyndallization is also known as __________________.
14) Define- Natural Dyes
15) Name the process of destructing microorganisms by burning into the flame of the Bunsen burner.
16) Give one example of a substance used to preserve cultures for cryopreservation.
17) Iodine is traditionally used as germicidal agent in a form as _________________.
18) State whether true or false.
Bactericidal agents kill viruses.
19) Give one example of a gaseous agent that has germicidal activity.
20)The time taken for a population to double in the regular interval of time is called ____________.
Q. 2) A) What is the resolving power of a microscope? How can resolving power be increased? (8M)
Q. 2) B) Name several differential staining techniques and describe the type of information each provides. (7M)
OR
Q. 2) C) Elaborate on different theories of staining. (8M)
Q. 2) D) What are the underlying principle, advantages, and disadvantages of Darkfield microscope? (7M)
Q.3A) List several different kinds of radiations used for the destruction of microorganisms. Comment on mode of action of any two of its examples. (8M)
Q.3) B) Describe filtration as a physical agent for control of microorganisms. (7M)
OR
Q. 3) C) List several halogens & compounds of halogens to control microbial population. Add a note on practical applications of any two such compounds. (8M)
Q. 3) D) Explain in brief the usage and limitations of any four chemical agents for control of microorganisms. (7M)
Q. 4) A) Elaborate on significance of nutritional requirements of microorganisms with respect to Nitrogen, Carbon, Phosphorous, Sulphur, growth factors, and trace elements. (8M)
Q. 4) B) Explain the term pure culture. How would you get the pure culture from the mixed population by isolation technique? (7M)
OR
Q. 4) C) How would you enumerate microorganisms indirectly by determining the Nitrogen content and dry weight of the cells? (8M)
Q. 4) D) What is cryopreservation? Explain in detail the method and advantages of cryopreservation. (7M)
Q. 5) Write short notes on the following. (Any three) (15M)
1) Acid and basic dyes
2) Functions of Fixative
3) Incineration
4) Alcohol as antimicrobial agent
5) Synchronous growth
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