Cell Structure and Organization: Examining Animal and Plant Cells

Cell Structure and Organization

Examining Animal and Plant Cells

Plant and animal cells have similarities and differences. Plant cells have a cell wall which gives it a de nite shape. Animal cells only have a cell membrane and thus a less rigid structure. Both types of cells have a nucleus which controls the function of the cell. Cells have different types of structures depending on their function in the organism.

Learning Objectives

To differentiate various types of cells.

Materials

Water drop microscope*, plastic slides*, cover slips*, needle*, iodine solu-tion*, Gentian Violet stain*, white tiles*, beaker*, petri dish*, onion, soft tissues from plants, blotting paper*, cheek cells, and razor blade/sharp knife, toothpick.

Hazards and Safety

Gentian Violet can stain the skin and clothes.

Preparation Procedure

1.           Collect a few cheek cells from the inside of your cheek using a toothpick. Run a few drops of water over the toothpick onto a slide. Cover with a cover slip.

Activity Procedure

1.           Collect all materials

2.           Peel a thin layer of epidermal cells from the onion and stain them using a few drops of iodine solution.

3.           Cut a few thin cross sections from the stem and root using a sharp razor blade and place the specimens into a petri dish with water and a few drops of Gentian Violet.

4.           Select the thinnest section of a stem and root and place the specimens on a slide.

5.           Observe each specimen with the water drop microscope and draw what you see.

Figure 6.1: Cheek cells as viewed through the water drop microscope

Figure 6.2: Plant cells as viewed through the water drop microscope

Results and Conclusion

The activity is intended to enable you to observe the structure of different plant cells.

Clean Up Procedure

1.           Collect all the used materials, cleaning and storing items that will be used later.

2.           Gentian Violet should be reused if possible; waste Gentian Violet should be disposed of in the pit latrine.

Notes

While observing the animal and plant cells under a water drop microscope, you will only see the layout of the cells but not the details of different or-ganelles as with a light microscope.