Microscopes: parts, types and total magnification

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   A drawing of a cell is 36 mm long and made at 900×. Ari wants the real cell's length. How long is it?

   • 400 µm
   • 0.04 µm
   • 32,400 µm
   • 40 µm
2. 2.

   A photo shows a cell 60 mm long. Bo knows the real cell is 30 µm long. What is the magnification?

   • 200×
   • 2×
   • 2,000×
   • 1,800,000×

3. Read this first

   Red blood cell on a photo (example data)

   item	length on the photo (mm)	real length (µm)
   scale bar	25	5
   red blood cell	40	?

4. 3.

   Esme uses the photo's scale bar to size a red blood cell. How wide is the real cell?

   • 200 µm
   • 8 µm
   • 3.1 µm
   • 8 mm
5. 4.

   1 mm = 1,000 µm. Jun reads two real sizes. How many red blood cells fit side by side across the pinhead?

   • 16,000 cells
   • 250 cells
   • 0.25 cells
   • 25 cells
6. 5.

   1 µm = 1,000 nm. Kira views a rod-shaped bacterium 0.5 µm long. Can a light microscope show its two ends as separate points?

   • An electron microscope could separate them, but a light one could not
   • No, but a stronger eyepiece would separate them
   • No: 0.5 is smaller than 200, so it is too small
   • Yes: 0.5 µm is 500 nm, which is more than 200 nm

7. Field of view (example data)

   total magnification	field diameter (mm)
   100×	1.8
   400×	0.45

8. 6.

   The field of view is 1.8 mm wide at 100×. Milo switches to 400×. How wide is the field now?

   • 0.045 mm
   • 0.45 mm
   • 0.9 mm
   • 7.2 mm
9. 7.

   1 mm = 1,000 µm. Noah reads that the 400× field is 0.45 mm wide. About how many red blood cells (8 µm) fit side by side across it?

   • About 3,600 cells
   • About 5.6 cells
   • About 56 cells
   • About 0.056 cells
10. 8.

    1 mm = 1,000 µm. A cell spans one fifth of the 0.45 mm field at 400×. How long is Pia's cell?

    • 90 µm
    • 9 µm
    • 2,250 µm
    • 90 mm
11. 9.

    1 nm = 1,000 pm. Ren compares resolutions. How many times finer is the electron microscope's resolution than the light microscope's?

    • About 400 times finer
    • About 4 times finer
    • About 4,000,000 times finer
    • About 4,000 times finer

12. Two electron microscopes (facts from OpenStax Biology 2e)

    kind	how the beam works	what it shows
    scanning	moves back and forth across the surface	surface details
    transmission	passes through a thin slice	internal structures

13. 10.

    Zee wants to see the inside of a cell's nucleus and mitochondria. Which microscope works?

    • A scanning electron microscope, since electron beams show the inside too
    • A light microscope, since it shows inside structures finest
    • A scanning electron microscope, since it moves across the specimen
    • A transmission electron microscope, since its beam passes through a thin slice