experiment onion cell-biology
B04 onion skin lab
SNC 2D
Name:______________________________
Lab: Investigation of the Structure of Onions Cells
Purpose: To investigate the structure of onion cells and become familiar with some of the basic parts of a cell. This lab will also introduce you to the technique of preparing a wet mount slide.
Materials:
microscope pencil cover slips lens paper paper towels
blank white paper ruler known field of views beaker tweezers
glass slides eraser medicine dropper lens cleaning solution iodine solution (Lugol's solution)
Procedure:
____ 1. Place a check mark (√) in the space provided as you perform each step.
____ 2. Check the condition of your microscope and report any problems to your teacher.
____ 3. Obtain a sheet of lens tissue paper with lens cleaning solution and clean all the lenses of your microscope gently.
____ 4. Obtain a microscope glass slide. Hold it by the edges and wet it with water. Wipe both sides dry with a paper towel. Always hold the slide by the edges or you will leave fingerprints on the slide. ____5. Clean the coverslip in a similar manner. CAUTION: It is very fragile. You can avoid breaking it by wiping both sides at once as shown in figure 1.
____6. Using the medicine dropper, place one drop of water near the centre of the glass slide. This water is called a mounting medium. It helps produce a clear image.
____7. Hold a piece of onion bulb scale so that the concave
(inner) surface faces you. Then snap it backwards as shown in figure 2. You should now be able to see a thin, transparent "skin" or epidermis, on the concave surface.
____8. Use the tweezers or your fingernails to pull off a piece of this epidermis.
____9. Place the piece of epidermis in the drop of water. Avoid wrinkling the epidermis. If wrinkles develop, use the tweezers to gently unwrinkle the tissue without tearing it.
1
B04 onion skin lab
____10. Hold a
SNC 2D
Name:______________________________
Lab: Investigation of the Structure of Onions Cells
Purpose: To investigate the structure of onion cells and become familiar with some of the basic parts of a cell. This lab will also introduce you to the technique of preparing a wet mount slide.
Materials:
microscope pencil cover slips lens paper paper towels
blank white paper ruler known field of views beaker tweezers
glass slides eraser medicine dropper lens cleaning solution iodine solution (Lugol's solution)
Procedure:
____ 1. Place a check mark (√) in the space provided as you perform each step.
____ 2. Check the condition of your microscope and report any problems to your teacher.
____ 3. Obtain a sheet of lens tissue paper with lens cleaning solution and clean all the lenses of your microscope gently.
____ 4. Obtain a microscope glass slide. Hold it by the edges and wet it with water. Wipe both sides dry with a paper towel. Always hold the slide by the edges or you will leave fingerprints on the slide. ____5. Clean the coverslip in a similar manner. CAUTION: It is very fragile. You can avoid breaking it by wiping both sides at once as shown in figure 1.
____6. Using the medicine dropper, place one drop of water near the centre of the glass slide. This water is called a mounting medium. It helps produce a clear image.
____7. Hold a piece of onion bulb scale so that the concave
(inner) surface faces you. Then snap it backwards as shown in figure 2. You should now be able to see a thin, transparent "skin" or epidermis, on the concave surface.
____8. Use the tweezers or your fingernails to pull off a piece of this epidermis.
____9. Place the piece of epidermis in the drop of water. Avoid wrinkling the epidermis. If wrinkles develop, use the tweezers to gently unwrinkle the tissue without tearing it.
1
B04 onion skin lab
____10. Hold a