A. Fill in the blanks :-
1. Micro-organisms can be seen with the aid of ___________ .
Ans – Microscope.
2. Bacteria normally multiply by ______________ .
Ans – Binary fission.
3. Disease producing microbes are called __________ .
Ans – Pathogens.
4. The poisonous substances produced by some pathogenic bacteria are known as __________ .
Ans – Toxins.
5. Algae can make their own food because they can ____________ .
Ans – Photosynthesise.
6. The chief source of food for fishes is ___________ .
Ans – Algae.
7. The product of algae used for raising bacterial culture is called __________ .
Ans – Agar.
8. Algae are plant-like but _______ are animal-like.
Ans – Protozoans.
9. Mushroom is a type of _________ .
Ans – Fungus.
10. Micro-organisms which form the borderline between the living and non-living world are called __
Ans – Viruses.
11. Entamoeba causes the disease ________ .
Ans – Amoebic dysentery.
12. Ring worm is a skin disease caused by _____ .
Ans – Fungus.
13. In the roots of the nodulated plants, nitrogen-fixing bacteria are present. They are known as ___
Ans – Rhizobium.
14. ______ is a disease caused by fungus in wheat plants.
Ans – Wheat rust.
15. All mushrooms are not ______ .
Ans – Edible.
16. The bacteria which help in the formation of dahi (curd) is called _______ .
Ans – Lactobacillus.
17. Common cold is caused by _______ infections.
Ans – Virus.
18. Penicillin was discovered by _________ .
Ans – Alexander Flemming.
19. Classification of living organisms is based on ______ characters.
Ans – Similar.
20. The insects which act as carriers are called _______ .
Ans – Vectors.
B. Answer the following questions:-
1. Name four antibiotics.
Ans – Pecicillin, Streptromycin, Tetracycline, Gramicidin
2. Name the major groups of micro-organisms.
Ans – The major groups of micro-organisms are :- Bacteria, Fungi, Protozoa, Algae, Viruses
3. What are the two groups of organisms in fungi?
Ans – Fungi consists of two main groups:- Yeast and Mould
4. Name the diseases caused by viruses.
Ans- Diseases caused by viruses are : Polio-myelitis, Viral dysentery, Cold and fever, Flu (influenza), Measlles.
5. Why antibiotics have no effect on viruses ?
Ans – Antibiotics have no effect on viruses because they do not have a metabolism of their own.
6. Who is the father of bacteriology?
Ans – Louis Pasteur.
7. Who first of all used microscope to observe bacteria?
Ans – Antony Von Leeuwenhock.
8. Name three diseases caused by bacteria.
Ans – Typhoid, Cholera, T.B.
9. Name three diseases caused by protozoa.
Ans- Malaria, Dysentery, Kalaazar.
10. Which micro-organism is used in the preparation of bread and alcohol?
Ans – Yeast.
CBSE AND ICSE SOLVER 