Name_________________________ Period___________

CELL LAB

PART 1: ELODEA CELLS

OBJECTIVE: TO OBSERVE CELLS WITH CHLOROPLASTS

MATERIALS: ELODEA LEAF, SLIDE, COVER SLIP

PROCEDURE:

1. Remove ONE fresh, green leaf from an Elodea plant.

2. Place the leaf on a slide and add ONE drop of water and a cover slip.

3. Observe under low power.

4. Select an area where the cells are clearly visible and bring it into focus under high power.

5. Draw ONE cell in the space provided. Label the following: CELL WALL, CELL MEMBRANE, NUCLEUS (IF VISIBLE), CHLOROPLAST, CYTOPLASM

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QUESTIONS:

1. What is the shape of the Elodea cells? How does their shape compare to the cheek cells?

2. What are the green organelles? What is their function?

PART 2: ONION CELLS

OBJECTIVE: TO LOOK COMPARE A PLANT CELL TO AN ANIMAL CELL

MATERIALS: ONION, IODINE, SLIDE, COVER SLIP

PROCEDURE:

1. Peel some thin, transparent tissue from the inner surface of an onion.

2. Place it on a slide.

3. Add ONE drop of iodine before putting on the cover slip.

4. Examine under low power then high power.

5. Make a drawing of ONE onion cell labeling the following: CELL WALL, CELL MEMBRANE, NUCLEUS, CYTOPLASM

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QUESTIONS:

1. What effect does iodine have on the cells?

2. What are the similarities between the Elodea cell and the onion cell? What are the differences? What possible reasons could there be for those differences?

PART 3: CHEEK CELLS

OBJECTIVE: TO OBSERVE AN ANIMAL CELL AND COMPARE IT TO PLANT CELLS

MATERIALS: TOOTHPICK, SLIDE, COVER SLIP, IODINE

PROCEDURE:

1. GENTLY scrape the inside of your cheek with a toothpick.

2. Rub the end of the toothpick in a drop of water on a clean slide.

3. THROW THE TOOTHPICK IN THE TRASHCAN!

4. Add ONE drop of iodine to the slide before putting on the cover slip.

5. Observe under low power.

6. Focus on one small, brown dot.

7. Switch to high power and draw ONE cell labeling the following: CELL MEMBRANE, CYTOPLASM, NUCLEUS, NUCLEAR MEMBRANE

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QUESTIONS:

1. Find the edge of the cytoplasm. How is it different from the cell walls in onion and Elodea cells?

2. Study several different cells under high power. Does the cell have a definite shape? Why or why not?

3. Do all cells have a nucleus? Where is it generally located in the cells you have seen?