Cell Lab Instructions

Purpose: To make observations of plant and animal cells and learn some of the differences and similarities that exist between them.

Part A: Elodea Cells (plant)

  1. With forceps, remove a young leaf from near the tip of an Elodea plant.
  2. Place the leaf in a drop of water in the center of a slide, cover with a cover slip, and observe under low,intermediate,and high power.
  3. Under high power magnification, as the slide begins to warm up, you will see the chloroplasts and cytoplasm begin to move or stream inside the cell. This streaming process is known as cyclosis.
  4. Answer questions 1-4 before going on.

Part B: Onion Cells (plant)

  1. With forceps, carefully remove a very thin layer of onion skin. (The inner side of the skin may be readily peeled.)
  2. Make a wet mount slide of the onion. (Make sure onion skin does not fold over on itself.)
  3. To see the nucleus of the cell better, you will have to stain the onion skin with iodine. Add one drop of iodine to the onion skin and cover with a cover slip.
  4. Observe using low,intermediate and high power.
  5. Answer questions 5-9.

Part C: Cheek Cells (animal)

  1. Obtain a prepared slide containing human cheek cells. The cells have been stained with methylene blue. Observe the cells on low, intermediate and high power.
  2. Answer questions 10-13.

Part D: Cork Cells (plant)

1. Obtain a very thin slice of cork.

2. Make a wet mount slide.

3. Observe using low, intermediate, and high power.

4. Answer questions14-16.

Part E: Skin cells (animal)

1. Cut a piece of clear packing tape about 2cm x 2cm or to fit on the slide.

2. Place the packing tape on the inside of your wrist. Rub the tape so

that it adheres to your skin cells. Quickly remove the tape.

3. Place the tape sticky side up on a microscope slide. Place a drop of

iodine on the tape. Place a coverslip over the iodine on the tape.

4. Observe under low, intermediate, and high power.

5. Answer questions 17-20.

Cell Lab Questions

Questions

  1. **Make a drawing of one Elodea cell as you observe it under high power and record the total magnification. Label the CELL WALL, GREEN CHLOROPLAST, and CYTOPLASM. Label the NUCLEUS if you see it.
  2. Write some general observations about the Elodea cell: shape, color, appearance, etc.
  3. Were you able to see the streaming movement of the cytoplasm? If so, which direction did it flow (clockwise or counter clockwise)?
  4. What is the function of cyclosis? What is your best idea?
  1. **Drawone onion cell on high power and record the total magnification. Label the CELL WALL, CYTOPLASM and NUCLEUS.
  2. Write some general observations about the appearance of the onion cell.
  3. What structures usually found in plant cells are missing in the onion cell? Why?
  4. Therefore, what process can’t the onion carry out?
  5. What then is the function of an onion to the plant?
  1. **Make a drawing of cheek cells on high power and record the total magnification. Label the NUCLEUS, CYTOPLASM and CELL MEMBRANE.
  2. Write some general observations of this animal cell.
  3. What structure previously seen in plant cells are absent from human cells?
  4. Why is the cheek cell stained blue?
  1. **Make a drawing of several cork cells on high power. Label the CELL WALL.
  2. Write some general observations of the cork cell.
  3. Why is the space inside the cell wall empty?
  1. **Make a drawing of several skin cells on high power and record the total magnification. Label the NUCLEUS, CYTOPLASM, AND CELL MEMBRANE.
  2. Write some general observations of this animal cell.
  3. In what ways does it resemble the cheek cells.
  1. In what ways are the onion cell, the Elodea leaf cell the human cheek cell and the human skin cell alike and in what ways are they different?

CELL LAB ANSWER SHEET NAME______

CELL LAB ANSWER SHEET NAME______

Complete the following chart about the cells you observed. If you saw the structure place a in the box.

Cell membrane / Cell wall / Nucleus / Cytoplasm / Chloroplast / Eukaryote or Prokaryote (E or P)
Elodea
Onion
Cork
Cheek Cell
Skin

Attach another sheet of paper with your answers to the questions on it.