CLASS -8 

(Microorganism: Friend and Foe)

Multiple Choice Question- (1 Marks Each)

1.Bacteria are classified according to their:

	i) Shape	ii) size		iii) color		iv) none of these
2.	The first antibiotic discovered was:
	i) Penicillin	ii) Tetracycline		iii) Streptomycin		iv) Bacitracin
3.	Cholera is caused by:
	i) vibrio cholera	ii) clostridium tetani iii) salmonella typhi					iv) none of these
4.	A common bacterial disease in plants is:
	i) Citrus canker	ii) Rabies		iii) Polio		iv) All of these
5.A common food preservative is:
	i) Benzoic acid	ii) Hydrochloric acid iii) Sulphuric acid						iv) Nitric acid
6.	An edible fungi is:
	i) Mould	ii) Mushroom		iii) Algae		iv) None of these
7.	The smallest microorganism is:
	i) Algae	ii) Protozoan		iii) Bacterium		iv) Virus
8.	Algae are:
	i) Autotrophs ii) Parasites iii) Heterotrophy				iv) Saprophytes
9.	The microorganisms that play an important role in maintaining the balance of							nitrogen gas in the
	atmosphere are:
	i) Bacteria	ii) Algae	iii) Virus		iv) Protozoa

10. Which of these are added to dough to make it rise?

i) Yeast

ii) Algae

iii) garbage

iv) all of these

Fill in the blanks:- (1 Marks Each)

1.Microorganisms can be seen with the help of a ……………………..

2.Blue green algae fix ……………….. Directly from air to enhance fertility of soil.

3.Alcohol is produced with the help of ……………………….

4.Cholera is caused by …………………….

5.………………….. are non-green plants.

6.………………….. cause fermentation.

7.……………………….. and ………………………. Are diseases caused by fungi in humans.

8.A ………………….. found in the intestine of termite, help them to digest word cellulose.

9.…………………… only multiply in the body of a living organism.

10.……………….. is a fatal disease of humans as well as cattle.

Very Short Answer Question: (1 Marks Each)

1.Write the names of some diseases caused by virus.

2.What is the main ingredient of rava idlis and bhaturas.

3.What is fermentation?

4.Mention tow groups of Microorganisms on the basis of their functions?

5.Name some diseases caused by protozaans.

Short answer questions:

(2 Marks Each)

1.What are microorganisms?

2.How do microbes survive in adverse conditions?

3.How bacteria are useful to us?

4.What is virus?

5.What is fermentation? Where is it used?

6.Write two common bacterial disease of human and write preventive measures for it?

7.What is the role of yeast in baking industry ?

8.Write sum commercial use of microorganisms?

9.What is pasteurization of milk?

10.How do microorganisms spoil food?

Answer these question		(3 Marks Each)
1.	What are major groups of microorganisms?
2.	Draw any protozoa and Label its part.
3.	What are the antibiotics? What precautions one should take while taking them?
4.	How do bacteria help in increasing soil fertility? Explain.
5.	Classify the bacteria according to their shape.
6.	What are communicable diseases ? Explain with examples.
7.	What do you mean by food poisoning ?
8.	Explain how does a vaccine work?
9.	Describe the role of blue green alae and bacteria in fertility of soil ?
10.	Give one example of each.

i) an edible fungi	ii) antibiotic obtained from fungi
iii) a parasitic protozoan	iv) nitrogen fixing bacteria
v) a bacteria residing in intestines of man	vi) what is nitrogen cycle
Long answer questions.	(5 Marks Each)

1.Draw and explain the harmfull effects of bactria with Example.

2.What are food preservatives ? Explain some common food preservatives.

3.Explain cousative microorganisms, mode of transmission and preventive measure of the humand diseases like Tuberculosis, Measles, Chicken pox, Polio, Cholera, Typhoid, Hepatitis B and Maleria etc.

4.Explain Nitrogen Cycle with the help of Label Diagram?

5.Draw different types of fungi and write useful and harmful effect of fungi.