CBSE Class 8 Science The Invisible Living World: Beyond Our Naked Eye (Class 8 NCERT New) Quiz 18

1. Suppose you observe a single-celled organism in pond water that moves with the help of specialized structures and is not green. Based on the table, which microorganism is it most likely to be?

A Algae B Amoeba C Paramecium D Fungi

2. Which organism present in soil suspension has a branched filament without chlorophyll and a sac-like structure?

A Bread mould (Fungi) B Algae C Bacteria D Mould (Fungi)

3. What is the main difference between the structure of bread mould and mould (both fungi) as described in the table?

A Bread mould has a sac-like structure, while mould has a brush-like structure. B Bread mould has chlorophyll, while mould does not. C Bread mould is spherical, while mould is rod-shaped. D Bread mould has hair-like projections, while mould does not.

4. Which organism in the table is described as spherical and contains chlorophyll—a green pigment?

A Algae B Bread mould (Fungi) C Bacteria D Mould (Fungi)

5. Bacteria in soil suspension can have which of the following shapes?

A Spherical, comma, spiral, or rod-shaped B Only spherical C Only rod-shaped D Only spiral

6. Why do microorganisms play an important role in our lives, despite their small size?

A They are everywhere and can affect plants, animals, and humans. B They are only found in soil. C They are visible to the naked eye. D They do not cause any diseases.

7. What device is used to observe microorganisms that cannot be seen with the naked eye?

A Microscope B Telescope C Magnifying glass D Binoculars

8. Viruses are described as acellular and microscopic. What happens when viruses enter a living cell?

A They multiply. B They disappear. C They become visible to the naked eye. D They turn into bacteria.

9. Which of the following statements about viruses is correct?

A Viruses may infect plants, animals, or bacterial cells and may cause a disease. B Viruses are always beneficial to humans. C Viruses are visible without a microscope. D Viruses contain chlorophyll.

10. Where can microorganisms be found?

A Only in water B Only in soil C Only in air D In water, soil, air, and some food items