BSc.-Basic Life Sciences -II: Microbial Techniques-Mumbai-April 2018
MUMBAI UNIVERSITY
Subject: Basic Life Sciences -II: Microbial Techniques
Semester: 1
[Total Time: 2 ½ hours]
[Total Marks: 75 ]
Note: 1) Attempt questions
2) All questions can al marks
3) Draw a labeled diagram forever necessary S SE
4) For Q2, Q3, and 4 sent A and OR C and D.
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Q. 1 Do as directed: (Any fifteen) (15M)
1) Define: Differential staining.
2) Define Warding distance.
3) Give one example of a Gram-positive bacterium.
4) Give one example of a Natural day.
5) Give the significance of an Immersion objective.
6) Fill in the blank: Working distance of an object covered with a thick coverslip will be _______ than that of an uncovered object ( more/less)
7) Give the term for the detect in the microscope objective which causes diffusion of light in the center leading to ring structure.
8) Define. Disinfection.
Give one Example
9) Non-ionising radiation.
10) Source of ionizing radiations.
11) Alcohol used a sterilant.
12) Surface active agent.
13) How would you sterilize pre-packed syringes and catheters?
14) How would you sterilize enclosed areas like PTC laboratory?
15) Define. Chemoheterotrophs.
16) Define. Cryopreservation.
17) fill in the blanks. The time taken for the population to double in size is called _____________ time.
18) Fill in the blank: when microorganisms are introduced into fresh culture medium, usually immediate increase in cell number occurs, so this period is called the ___________ phase.
19) Give one example of an Indirect method to enumerate microorganisms
20) Give one example of Selective media.
Q. 2) A) Elaborate the terms ‘chromophore’ and ‘autochrome. State any two chemical groups of stains with examples. (8M)
Q. 2) B) Explain the optical arrangement and applications of a phase-contrast microscope. (7M)
OR
Q. 2) C) what is the difference between a simple and compound microscope? Explain the significance of ‘resolving power’ and ‘numerical aperture. (8M)
Q. 2) D) Illustrate the principle and method of Gram staining. (7M)
Q. 3) A) Discuss in brief characteristics of an ideal disinfectant. Add a note on methods to determine the potency of a disinfectant. (8M)
Q. 3) B) Describe role of dyes in antisepsis. (7M)
OR
Q. 3) C) Using suitable examples explain the role of gases in sterilization, fumigation, or disinfection. (8M)
Q. 3) D) What is the role of aldehydes as microbiocidal agents? (7M)
Q. 4) A) Elaborate on the chemical and physical types of culture media. (8M)
Q. 4) B) What do you mean by batch culture? Elaborate on the different phases of the growth curve of organisms in batch culture. (7M)
OR
Q. 4) C) Discuss the direct methods used to enumerate microorganisms? (8M)
Q. 4) D) Explain how you would preserve the microorganisms under lower temperatures. (7M)
Q. 5) Write short notes on ( Any Three) (15M)
a) Ziehl-Nielsen Staining.
b) Darkfield microscope.
c) Role of ionizing radiation in sterilization.
d) Phenolic compounds as microbicidal agents.
e) Turbidostate.
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