Observing Plant and Animal Cells

OBSERVING PLANT AND ANIMAL CELLS

A cell is the smallest unit that can carry out life processes. Although all cells have certain characteristics in common, cells can vary in size, shape, and structure. In this investigation, you will use a microscope to examine a variety of plant and animal cells.

OBJECTIVES

-Examine the structure of cells.

-Identify similarities and differences in animal and plant cells.

MATERIALS

Droppercoverslipsforceps

Slidesmicroscopepaper towel

TapeelodeaMethylene Blue solution

PROCEDURE

1. Wash the underside of a wrist that will be sampled for epidermal cells with soap and water.

2. Stick a clean piece of clear tape on the underside of the washed wrist.

3. Gently remove the piece of tape from the wrist being careful to avoid getting fingerprints on the tape. A forceps might help to remove the tape and avoid fingerprinting the tape.

4. Place the tape, sticky-side up, on a clean microscope slide.

5. Stain the top, sticky side of the tape with 2 or 3 drops of 1% methylene blue solution.

6. Place a cover slip over the sticky tape. (Tweezers may help you avoid staining your fingertips.)

7. Under low power locate single skin cells. Switch to medium, then high power to observe them more closely. Draw a single skin cell. Label the nucleus, cytoplasm and cell membrane.

8. Remove a leaf from the tip of an elodea plant. Place it on a slide, add a drop of water, and cover it with a coverslip.

9. Examine the elodea cells under low power. Notice the elodea leaf is only a few layers thick. Adjust the focus to observe just one layer. Switch to medium, then high power. Draw an elodea cell and label the cell wall, nucleus, cytoplasm, cell membrane, and chloroplasts.

10. Create a data table like the one on the back of this sheet in your lab report.

Observe the three unknown slides and determine if they are animal or plant cells. Record the answers in the table. Provide your reasoning why in the table as well.

ANALYSIS AND CONCLUSIONS

1. How are the skin cell and elodea cell similar? Different?

2. Describe the shape and location of the chloroplasts in the elodea cell.

3. Did you see movement in any of the cells? If so, which one?

4. A detective, called to scene of a crime, collected samples of tissues found nearby. How could he tell whether these tissues were from a plant or an animal?