Science Microorgnisms Assignment

DAV PUBLIC SCHOOL, SECTOR-VI, DWARKA

ASSIGNMENT

CLASS – VIII

MICROORGANISIM- FRIENDS OR FOES

Q1. What are micro-organisms?

 Q2. Write a short note on viruses.

 Q3. Write a note on presence of various microbes in nature.

Q4. How are micro-organisms beneficial to mankind?

 Q5. Why are chidren given vaccines?

Q6. How do micro-organisms help in cleaning up of the environment?

Q7. Write a note on harmful micro-organisms.

Q8. What are the various methods of food preservation?

 Q9. What is pasteurization?

Q10. Discuss symbiotic relationship of rhizobium with plants

Q11. Discuss nitrogen cycle occurring in nature.

12. Tick the correct option:

1. The yeast multiply by a process called

(a)    Binary fission                                                 (b)   Budding

(c)    Spore formation                                           (d)   None of the above

2.  The example of protozoan is

(a)    Penicillium                                                   (b)   Blue green algae

(c)    Amoeba                                                        (d)   Bacillus

3.   The most common carrier of communicable diseases is

(a)    Ant                                                                (b)   Housefly

(c)    Dragonfly                                                  (d)   Spider

4.   The following is an antibiotics

(a)    Alcohol                                                     (b)   Yeast

(c)    Sodium bicarbonate                           (d)   Streptomycin

5.   Yeast produces alcohol and carbon dioxide by a process called

(a)    Evaporation                                          (b)   Respiration

(c)    Fermentation                                        (d)   Digestion

6. The algae commonly used as fertilizers are called

(a)    Staphylococcus                                   (b)   Diatoms

(c)    Blue green algae                                 (d)   None of the above

7.     Cholera is caused by

(a)    Bacteria                                                (b)   Virus

(c)    Protozoa                                              (d)   Fungi

8. Plant disease citrus canker is caused by

(a)    Virus                                                       (b)   Fungi

(c)    Bacteria                                                 (d)   None of these

9.  The bread dough rises because of

(a)    Kneading                                                (b)   Heat

(c)    Grinding                                                 (d)   Growth of yeast cells

10.  Carrier of dengue virus is

(a)    House fly                                              (b)   Dragon fly

(c)    Female Aedes Mosquito               (d)   Butterfly

11.  Yeast is used in the production of

(a)    Sugar                                                     (b)   Alcohol

(c)    Hydrochloric acid                           (d)   Oxygen

12.  The vaccine for smallpox was discovered by

(a)    Robert Koch                                   (b)   Alexander Fleming

(c)    Sir Ronald Ross                             (d)   Edward Jenner

13. Chickenpox is caused by

(a)    Virus                                                 (b)   Fungi

(c)    Protozoa                                         (d)   Bacteria

14.  The bacterium which promote the formation of curd

(a)    Rhizobium                                      (b)    Spirogyra

(c)    Bread mould                                 (d)   Lactobacillus

15.Plasmodium is a human parasite which causes

(a)    dysentery                                       (b)   Sleeping sickness

(c)    Malaria                                            (d)   All of the above

16.  The bacterium Bacillus Anthracis was discovered by

(a)    Edward Jenner                             (b)   Alexander Fleming

(c)    Louis Pasteur                                (d)   Robert Koch

17.   Carrier of malaria causing protozoan is

(a)    Butterfly                                            (b)   Housefly

(c)    Female Anopheles Mosquito   (d)   Cockroach

18.  The process of conversion of sugar into alcohol is called

(a)    Infection                                          (b)   Moulding

(c)    Nitrogen fixation                         (d)   Fermentation

19.   Foot and mouth disease of cattle is caused by

(a)    Fungi                                                   (b)   Virus

(c)    Algae                                                   (d)   None of these

20.  Which of the following is not a fungi

(a)    Paramecium                                      (b)   Bread mould

(c)    Penicillium                                         (d)   Aspergillus 

13. Write the contributions of the following:

A. Louis Pasteur               B. Edward Jenner   C. Alexander Fleming     D. Robert Koch

14. Define:

A. Microbes                       B. Pathogens                        C. Nitrogen Fixation

D. Pasteurization             E. Preservatives                 F. Carriers                     G. Fermentation

15. Give two uses of microorganisms in the following areas:

i) Food Industry            ii) Medicinal Use               iii) Environment related

16. Give an activity to show the process of fermentation?

17. List few differences between Antibiotics and Antibodies?

18. List some harmful effects of microorganism?

19. How can we control the spread of diseases caused by mosquitoes?

20.Why does sugar solution with yeast powder become alcoholic in taste?