WORKSHEET 3
SHORT ANSWER TYPE QUESTION (2 mark)
1. List two beneficial role of LAB in curd. (2)
2. Alexander Fleming while working on Staphylococci bacteria, once observed a mould growing in
one of his unwanted culture plate around which Staphylococci could not grow. Which was the
mould that contaminated his culture plate. Mention the significance of this observation. (2)
SHORTANSWER TYPE QUESTION ( 3 Marks)
3. Certain fungi forms symbiotic association with the roots of higher plants and both partners gain
benefit from this association. How is this association beneficial to plants? (3)
4. Organic farmers have started using microbes for controlling pests instead of pesticides. Name a
bacterium and a virus which are used as biocontrol agents. How this method is better than
pesticide based farming? (3)
5. The Eco club members of a school has donated portable biogas plant to their school for managing
lunch wastes. It is essential to add cow dung in the biogas plant initially for the generation of
biogas.
a. What is the purpose of adding cow dung in the biogas plant?
b. Name any three constituents of biogas.
c. How is the spent slurry useful? (3)
LONG ANSWER TYPE QUESTIONS ( 5 marks)
6. Name two different categories of microbes naturally occurring in sewage water. Explain their role
in cleaning sewage water into usable water.
7. Write a short notes on [a] Baker’s yeast [b] Alcohol [c]Statin [d]Brewer’s yeast [e] Streptokinase