Tutorial 1: Introduction to Microbiology
PTT 106: Microbiology
Sem II, 2011/2012
1. Discuss the advantages of the three-domain system.
2. List the characteristic of the bacteria, archaea and eukarya domain
3. Define spontaneous generation. Discuss on the Pasteur’s experiment with swan-neck flasks.
What did Pasteur prove when he showed that a cotton plug that had filtered air would
trigger the microbial growth when transferred to the medium?
4.
Describe Koch’s postulates. What is a pure culture? Why are pure cultures important to
Koch’s postulates?
Tutorial 2: Microscopy and Specimen Preparation
PTT 106: Microbiology
Sem II, 2011/2012
1. If a specimen is viewed using a 5x objective in a microscope with a 15x eyepiece, how many
times has the image been magnified?
2. How does resolution depend on the wavelength of light, refractive index and numerical
aperture?
3. Define fixation. Identify and describe the 2 types of fixation methods.
4. Define differential staining. Identify types of differential staining.
5. Describe the Gram-staining procedure and explain what happens to a bacterial cell at each
step. What step in the procedure could be omitted without losing the ability to distinguish
between gram-positive and gram-negative bacteria? Why?
6. Why does the transmission electron microscope (TEM) have much greater resolution than
the light microscope?
7. Describe in general terms how the TEM functions? Why must the TEM use high vacuum and
very thin section?
Tutorial 3: Prokaryote and eukaryote cells
PTT 106: Microbiology
Sem II, 2011/2012
1. List the functions of cell wall.
2. Compare and contrast the cell wall of gram-positive and gram-negative bacterium. Include
labelled drawings in your discussion.
3. Design an experiment that illustrates the cell wall’s role in protecting against lysis.
4. Describe each of the following plasmids and explain their importance:
a) conjugative plasmid
b) F factor
c) Col plasmid
d) virulence plasmid
e) metabolic plasmid
5. Compare and contrast bacterial and archaeal flagella.
6. Explain in a general way how bacteria move toward substances such as nutrients and away
fromtoxic materials.