CBSE Class 8 Science The Invisible Living World: Beyond Our Naked Eye (Class 8 NCERT New) Quiz 7

1. Microorganisms help recycle waste and return important nutrients to nature.

A True B False

2. Manure formation occurs at optimal temperature and appropriate moisture level.

A True B False

3. The diversity of microorganisms helps in our kitchen by:

A Aiding in food fermentation and preservation B Increasing the risk of food spoilage only C Making all foods taste bitter D Preventing the growth of any bacteria

4. Ananda Mohan Chakrabarty received a patent in 1980. What is a patent?

A A patent is a copyright given to a person so that no one else can copy, use or sell his/her invention without permission. B A patent is a government license that allows a person to use any invention freely. C A patent is a certificate given for artistic work. D A patent is a trademark for a company logo.

5. Which of the following problems can be solved with the help of microorganisms?

A Waste decomposition B Traffic management C Internet connectivity D Weather forecasting

6. What is the difference in the volume of dough in bowl A and bowl B after kneading?

A The difference in the volume of dough in bowl A and bowl B after kneading is 100 ml. B The difference in the volume of dough in bowl A and bowl B after kneading is 50 ml. C The difference in the volume of dough in bowl A and bowl B after kneading is 200 ml. D The difference in the volume of dough in bowl A and bowl B after kneading is 0 ml.

7. Which gas is present in high proportion in biogas?

A Oxygen B Methane C Nitrogen D Hydrogen

8. The dough in bowl A, where yeast was added, has risen slightly, become fluffy, and has a different smell compared to the dough kneaded without yeast. What is the role of yeast, and why did we add sugar and warm water to the flour?

A Yeast helps the dough rise by producing carbon dioxide, and sugar and warm water activate the yeast. B Yeast makes the dough harder, and sugar and warm water are used to sweeten the dough. C Yeast changes the color of the dough, and sugar and warm water are used to cool it down. D Yeast prevents the dough from rising, and sugar and warm water stop fermentation.

9. Yeast belongs to a group of microorganisms called fungi. Yeast grows well in warm conditions.

A True B False

10. Yeast produces carbon dioxide during its growth, which forms bubbles that make the dough soft and fluffy.

A True B False