CBSE Class 9 Science Cell: The Building Block of Life (Class 9 NCERT New) Quiz 6

1. A nanometer (nm) is defined as what fraction of a meter?

A One-millionth B One-billionth C One-thousandth D One-hundredth

2. Which knob on a light microscope is primarily used first to bring the specimen into general, coarse focus?

A Fine adjustment knob B Condenser knob C Coarse adjustment knob D Stage clip knob

3. Which part of the light microscope reflects external light upwards through the stage to illuminate the slide?

A Eyepiece B Mirror C Body tube D Handle

4. What type of electron microscope image shows the high-resolution details of the lower surface of a leaf?

A Light micrograph B Electron micrograph C X-ray radiograph D Macrograph

5. Which plant's leaf stomata are often used to demonstrate high-resolution details in Scanning Electron Microscope imaging?

A Rhoeo leaf B Onion leaf C Colocasia leaf D Neem leaf

6. What is the alternative name for the cell membrane?

A Cell wall B Plasma membrane C Nuclear envelope D Tonoplast

7. Why is the cell membrane described as "selectively permeable"?

A It allows all substances to pass freely. B It blocks every substance from moving across. C It allows certain substances to pass while blocking others. D It only permits water to exit but never enter.

8. In a laboratory experiment, what happens to a potato piece placed in plain water after one hour?

A It shrinks B It melts C It swells D It remains completely unchanged

9. In a laboratory experiment, what happens to a potato piece placed in a 20% salt or sugar solution?

A It swells B It shrinks C It catches fire D Its weight doubles

10. Why does a potato piece placed in plain water increase in weight?

A Salt molecules entered the potato cells. B Water molecules moved into the potato cells. C Sugar molecules left the potato cells. D The potato cells multiplied rapidly.