QUESTION 3
(20)
3.1. What is a pure culture?
(2)
3.2
Explain the basis of having a pure culture in a laboratory
(3)
3.3
What are the two advantages and two disadvantages of a pure culture?
(4)
3.4
Outline factors that may lead to increase in antibiotic disease resistance
in some microorganisms.
(3)
3:5
Briefly discuss how the composition of a media that is both selective and differential
such as mannitol salt agar (MSA) can isolate Staphylococcus aureus.
(8)
SECTION C
(40)
QUESTION 4
(20)
4.1
Describe the main stages of bacterial growth curve.
(8)
4.2
Several factors influence the effectiveness of antimicrobial treatment. Briefly
describe how the following factors influence the death of microbes.
4.2.1 Types of microorganisms
(3)
4.2.2 Environmental influences
(3)
4.3
Evaluate the significance of thermal death reduction time in food industry.
(3)
4.4
Evaluate the use of ionising radiation in the control the growth and spread of
microorganisms.
(3)
QUESTION 5
(20)
5.1
Discuss the role of microorganism in the following industries.
5.1.1. Beer manufacturing
(5)
5.1.2 Extraction of low-grade ores.
(5)
5.2
Outline the role of microorganism in sewage and waste water treatment.
(10)
END OF QUESTION PAPER