Microorganisms friends and foe Worksheet-14

Microorganisms friends and foe Worksheet-14


Answer the following Questions:

  1. Describe the nitrogen cycle with the help of a nee and labelled diagram.

  2. (a) How do microorganisms spoil food?

(b) What are the chemical methods of preserving food material from the attack of microorganisms?


What are microorganisms? What are the five major groups of microorganisms?

Name three different habitats of microorganisms.

  1. (a) Differentiate between antibodies and antibiotics.

(b) Define vaccine.

(c) Explain the action of a vaccine.

  1. (a) Define preservation of food items.

(b) What are chemical preservatives?

(c) In what two ways can you preserve milk at home?

  1. (a) Define preservation.

(b) Explain four methods of preserving food.

  1. What do you mean by preservation? How will you preserve the following:

(a) Fruits and vegetables

(b) Milk?

  1. Write 10 lines on the usefulness of microorganisms in our lives.

  2. Write a short paragraph on the harms caused by microorganisms.

  3. How can we control the spread of malaria or dengue?

  4. (a)  Name two plant diseases.

(b) Name the microorganism causing the diseases and their mode of transmission.


Short Questions:

  1. Name two diseases caused by protozoans.

  2. What are antibiotics?

  3. What is a vaccine?

  4. What are communicable diseases?

  5. Name two carriers of disease-causing microbes.

  6. Which microorganism causes foot and mouth disease of cattle?

  7. Name one plant disease transmitted by insects and caused by virus.

  8. How is pasteurized milk obtained?

  9. How are viruses different from other microorganisms?

  10. Why do we use oil and vinegar to preserve vegetables and fruits?

  11. (a) Name the scientist who discovered the vaccine for smallpox.

       (b) Who discovered the bacterium which causes anthrax disease?

  1. What is pasteurization? Why do we boil milk before consuming it?

  2. Where do microorganisms live?

  3. What will happen if you take antibiotics when not needed?

  4. How is common cold spread?