Lesson T1.1.1

T1.1.1 Cells and light microscopy Quiz: KS3 Biology, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T1.1.1, Cells and light microscopy: 20 multiple choice questions for the KS3 Biology (National Curriculum), Unit 1: Structure and function of living organisms, written with Revision Ninja.

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The 20 questions

  1. Which structure is the basic building block of all living organisms?

    • The organ system
    • The tissue
    • The organ
    • The cell

  2. Which part of a light microscope do you look through?

    • Objective lens
    • Mirror
    • Eyepiece lens
    • Stage clip

  3. What does the stage of a light microscope hold in place?

    • Microscope slide
    • Eyepiece lens
    • Fine adjustment
    • Light source

  4. What does the diaphragm of a light microscope control?

    • Light intensity
    • Magnification
    • Slide position
    • Focus speed

  5. Why is a chemical stain added to cells before viewing under a microscope?

    • To improve contrast
    • To soften walls
    • To magnify image
    • To kill bacteria

  6. A microscope has an eyepiece lens of x10 and an objective lens of x40. What is the total magnification?

    • x50
    • x30
    • x4000
    • x400

  7. Which objective lens should you use first to find a specimen?

    • Highest power
    • Lowest power
    • Medium power
    • Immersion lens

  8. Why should a cover slip be lowered onto a microscope slide at an angle?

    • To dry sample
    • To flatten coverslip
    • To speed staining
    • To prevent air bubbles

  9. What is the real width of a cell measuring 5 cm at x100 magnification?

    • 0.005 mm
    • 0.5 mm
    • 50 mm
    • 5 mm

  10. Convert 0.5 mm into micrometres (µm).

    • 0.005 µm
    • 5000 µm
    • 500 µm
    • 50 µm

  11. Which rule must be followed when drawing biological cells seen under a microscope?

    • Use coloured pencils
    • Draw sketchy lines
    • Shade all areas
    • Use single clear lines

  12. What does microscope magnification actually measure?

    • Specimen actual size
    • Image size multiplier
    • Image clarity level
    • Light gathering power

  13. Which unit is commonly used to measure the size of very small cells?

    • Millilitre
    • Kilometre
    • Micrometre
    • Kilogram

  14. What is the primary purpose of a school light microscope?

    • Weigh tiny samples
    • Magnify small cells
    • Kill bacteria safely
    • Produce deep shadows

  15. A cell appears 4 cm across at x200 magnification. What is its actual width in mm?

    • 20 mm
    • 2 mm
    • 0.02 mm
    • 0.2 mm

  16. A cell is 0.02 mm across. How many micrometres is that?

    • 0.2 µm
    • 2 µm
    • 20 µm
    • 200 µm

  17. What happens to the field of view when microscope magnification is increased?

    • It gets larger
    • It turns darker
    • It gets smaller
    • It becomes blurred

  18. Why does very high magnification fail to show more detail with light?

    • Limited resolution
    • Thick cover slips
    • Weak batteries
    • Insufficient lighting

  19. A cell image is 10 cm wide and the real cell is 0.1 mm wide. What is the magnification?

    • x10
    • x100
    • x10000
    • x1000

  20. What is the correct first step when preparing a slide to view cells?

    • Add iodine stain
    • Place specimen on slide
    • Focus low power
    • Lower cover slip

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