The cytoskeleton The cytoskeleton is a network of protein filaments in the cytoplasm. It maintains the shape of the cell and is involved in cell movement and cell division . It forms various structures. Centrosome. This consists of two perpendicular, hollow cylinders, called centrioles. The centrioles are involved in the formation of cilia and f lagella , the organisation of the cytoskeleton , and the separation of the chromosomes during cell division . Cilia and f lagella. These are extensions of the cytoplasm that appear in certain cells. They help with cell movement. The cilia are small and abundant. The f lagella are long and few in number. Observe human cells under the microscope You will prepare a sample and observe buccal epithelium cells. 1. Scrape the inside of your cheek with a toothpick. Smear the sample across a glass slide and add a drop of water. Then heat the slide over the flame for a few seconds to fix the cells to the glass. 2. Add a few drops of methylene blue and let it sit for three minutes. Rinse the sample with water to eliminate any excess colouring. 3. Place a coverslip over the sample and press down. Make sure there are no air bubbles. 4. Observe the sample with different magnifications, starting with the lowest. 11 At what magnification was the sample visible? To find out, multiply the magnification power of the ocular lens by the power of the objective lens. For example, a 25x ocu l a r and a 10x objective gives us a total magnification of 250. Draw what you see at each magnification. Label the parts you see at the highest magnification. 12 a) Which part of the cell turns the most intense shade of blue? Which area of the cell looks almost granular? b) Given that cells form tissue, why do you think they are separated? Conclusions Steps Materials Glass slides and coverslips Alcohol burner Flat toothpick Methylene blue Microscope Staining cuvette 22 2. Human cells
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