Worksheet for chapter: Microorganisms: Friends and Foe is presented below. The worksheets are provided for practice and self evaluation of students of class 8. Solutions are provided at the end of the page.
(1)Write “T” against the sentences which are true and write “F” against the sentences which are false.
(i) Viruses are microorganisms.
(ii) Food can not preserved by using salt.
(iii) Microorganisms are responsible for maintaining the nitrogen in the atmosphere.
(iv) Air is not a mode of transmission of diseases.
(2) Define communicable diseases. Give some example of it.
(3) What are carriers? How they spread diseases among human?
(4) What is food preservation? Name some food preservatives?
(5)Define nitrogen cycle and explain it.
(6) Write a short note on diseases spread by microorganisms in plants.
Choose the correcr answeres:-
(7) Pasteurised milk can be drink without boiling. Yes /No
(8) Microorganisms are
(i) single celled
(ii) multi celled.
(9) Microorganisms can survive in
(i) cold areas
(10) Can taking antibiotics useful in cold or flu?