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How to Tell That an Onion Cell Has Depth

Onions, like all living organisms, are made up of many tiny cells. Under a microscope, the cells of an onion look much like a brick wall, due to its rectangular cells. At first glance under the low power of a microscope, an onion appears to have flat, simple cell structure. Upon further examination, however, it's possible to see more parts of an onion cell and conclude that it has depth.

Things You'll Need

Knife
Onion
Razor blade
Tweezers
Microscope slide
Cover slip
Microscope

Instructions

- 1
  Cut an onion into quarters. Pull out a small section of the innermost layer of the onion. Cut the piece of onion into several 1/2-cm squares using a sharp razor blade.
- 2
  Drop one drop of water on a microscope slide. The slide needs just enough water to keep the onion in place.
- 3
  Pick up one of the onion pieces with a pair of clean tweezers. Gently lay the onion on the slide, directly in the center of the water. Lay a cover slip on top of the onion and press out air bubbles.
- 4
  Set the slide on the stage of a microscope. Secure the slide in place with the stage clips.
- 5
  Turn on the microscope light and make sure the light shines through the onion. Adjust the slide if necessary.
- 6
  Look through the eyepiece of the microscope. Start with low-power magnification and take note of all the formations in the onion cell. If desired, draw a diagram to keep track of the appearance at low power.
- 7
  Adjust the magnification to medium or high power and examine the onion cell again. Compare the appearance to that of low power.
- 8
  Rotate the fine adjustment knob slowly to see the different layers of the onion cell. The different layers in the cell indicate depth.

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