Download tung and elodea lab

Name: _____________________________________________________ Date: __________________________________ Block: __________
“Tung” and Elodea Cell Exploration!
Objective: Students will be able to distinguish between a plant and animal cell using a light microscope.
Safety: Please wear aprons. The iodine will stain your clothing.
Materials:
Toothpick
Iodine
Microscope
Coverslip
Slide
Pipette
Elodea
Procedures: In this lab, you will be making wet mount slides of two cell types and comparing their
structure and parts.
“Tung” Cells:
1. Obtain a clean slide, coverslip, and toothpick.
2. Place a very small drop of water on the slide using a pipette.
3. With the toothpick, gently scrape your tongue and deposit a little of the scraping in the drop of
water by rolling the toothpick in the water.
4. Break up the mass of cells by stirring the toothpick until there is no longer a detectable mass of
cells. (This is called tongue cell soup.) The cells are transparent so you may not see much on the
slide at this point, but believe me they’re there!
5. Now, add a drop of iodine stain to the material on the slide.
6. Add a coverslip. Observe under low power. You may find some of the cells creased of piled up on
top of one another and some may be broken. Locate one or two cells that are clearly visible.
Center them on the stage and switch to medium power and then high power.
7. In the analysis section, draw one cell and label the cytoplasm, nucleus, and cell membrane.
Indicate the magnification.
Elodea Cells:
1. Obtain a clean slide, coverslip, and a small piece of Elodea.
2. Place a drop of water on the slide.
3. Break off one of the younger leaves near the tip of the branch.
4. Place it bottom side up in the drop of water on the slide.
5. Put on a coverslip. DO NOT USE STAIN. Observe under low and then medium power. Locate an
area where the cells are clearly visible (near the outside edge of the leaf) and then switch to high
power. This may be difficult to do because the leaf is several cell layers thick.
6. Look closely at the chloroplasts and in some cells (especially those near the center vein of the
leaf). You may observe their movement in the watery cytoplasm. They are passively carried
around the cell due to the streaming of the cytoplasm.
7. In the analysis section, draw one cell and label the cell wall, cytoplasm, and chloroplasts. Try to
locate the nucleus and central vacuole. Indicate where you would find the cell membrane. Also
indicate the magnification.
Analysis Section
Part A:
“Tung” Cell
Elodea Cell
Magnification: ____________________________________
Magnification: _______________________________________
Part B: “Tung” Cell Analysis
1. Describe the shape of a tongue cell. _____________________________________________________________________________
2. (a) Are tongue cells produced by plants or animals? ___________________________________________________________
(b) Is a cell wall present? _________________________________________________________________________________________
3. Are tongue cells alive? _________________________________ Explain _________________________________________________
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_________________________________________________________________________________________________________________________
4. Describe the location of the cell membrane. ____________________________________________________________________
5. What is the function of the cell membrane? ____________________________________________________________________
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6. (a) Describe the location of the cell’s cytoplasm. _______________________________________________________________
(b) Describe the appearance of the cytoplasm. _________________________________________________________________
7. What is the function of a cell’s cytoplasm? ______________________________________________________________________
_________________________________________________________________________________________________________________________
8. Why was a stain added to the tongue cells? _____________________________________________________________________
Part C: Elodea Cell Analysis
1. Describe the shape of the Elodea cell. ___________________________________________________________________________
2. (a) Is Elodea a plant or an animal? _______________________________________________________________________________
(b) Is a cell wall present? _________________________________________________________________________________________
3. Describe the shape and color of chloroplasts. __________________________________________________________________
4. Within what cell part already studied do chloroplasts lie? ____________________________________________________
5. What is the function of chloroplasts? ___________________________________________________________________________
_________________________________________________________________________________________________________________________
6. Are chloroplasts usually present in consumer cells? _________________________ Explain _______________________
_________________________________________________________________________________________________________________________
Part D: Complete the chart below. Indicate with check marks which organelles exist in animal and
plant cells.
Nucleus
Animal Cell
Plant Cell
Cell Wall
Cytoplasm
Nuclear
Membrane
Chloroplast
Cell
Membrane