NCERT Class VIII Science Solutions: Chapter 2-Microorganisms: Friend and Foe Part 2

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VERY SHORT ANSWER QUESTIONS

Question 8:

Unscramble the jumbled words underlined in the following statements.

  1. Cells of our body produce santiidobe to fight pathogens.

  2. Curbossulite is an air-borne disease caused by a bacterium.

  3. Xanrhat is a dangerous bacterial disease.

  4. Yeasts are used in the wine industry because of their property of meronettinaf.

Answer:

  1. Cells of our body produce antibodies to fight pathogens.

  2. Tuberculosis is an air-borne disease caused by a bacterium.

  3. Anthrax is a dangerous bacterial disease.

  4. Yeasts are used in the wine industry because of their property of fermentation.

Question 9:

Suggest a suitable word for each of the following statements.

  1. Chemicals added to food to prevent growth of microorganisms.

  2. Nitrogen-fixing microorganism present in the root nodules of legumes.

  3. Agent which spreads pathogens from one place to another.

  4. Chemicals which kill or stop the growth of pathogens.

Answer:

  1. Preservatives

  2. Rhizobium

  3. Carrier/vector

  4. Antibiotics

Question 10:

Match the names of scientists given in Column A with the discovery made by them given in Column B.

Match the Column a and Column B.(Q)
Match the Column A and Column B.(Q)

Column A

Column B

  1. Louis Pasteur

  • Penicillin

  • Robert Koch

  • Anthrax bacterium

  • Edward Jenner

  • Fermentation

  • Alexander Fleming

  • Small pox vaccine

  1. Typhoid

Answer:

Match the Column a and Column B.(A)
Match the Column A and Column B.(A)

Column A

Column B

  1. Louis Pasteur

iii Fermentation

  1. Robert Koch

ii Anthrax bacterium

  1. Edward Jenner

iv Small pox vaccine

  1. Alexander Fleming

i Penicillin

Question 11:

Name one commercial use of yeast.

Answer:

Baking bread/manufacture of alcoholic drinks

Question 12:

Name the process in yeast that converts sugars into alcohol.

Answer:

Fermentation

Image of process of fermentation

Image of Process of Fermentation

Image of process of fermentation

Question 13:

In the soil, which nutrient is enriched by blue-green algae (cyanobacteria)?

Answer:

Nitrogen

Question 14:

Why should we avoid standing close to a tuberculosis patient while he/she is coughing?

Answer:

Tuberculosis is an air-borne disease which easily spreads when the infected person coughs.

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