Peel off a thin and translucent onion skin, and place it on a glass slide. Add one drop of iodine solution, and cover the sample with a cover slip. The iodine works as a colorant, allowing the cell's structures to be observed under the microscope. Start observations with lower magnifications, increasing gradually and observing cell structures, such as the cell wall and membrane, the cytoplasm and the nucleus. Draw what you see at different magnifications.
Get a sample of pond water in a bucket. After about half an hour, gently pour some of the water out, leaving a smaller sample in the bottom. Collect some of this deposited water and sludge with a jar. Using a pipette, place a drop on a glass slide, gently covering with a slide cover. Observe the slide under the microscope, starting with lower magnifications. Describe what you see and formulate hypotheses about what it is. Observe and compare the water collected in different ponds, and then create a panel that shows the similarities and differences between the samples.
Children can observe their own cells by collecting a sample of cheek cell epithelium. Gently scrape the inside of a cheek with a toothpick. Smear the scrapings on a glass slide and add a drop of diluted methylene blue stain. Cover the sample with a cover slip and observe under the microscope at low light.
Plasmolysis happens when the membrane and cytoplasm of plant cells pull away from the cell wall due to excessive loss of water. Observe this phenomenon under a microscope. Create a 10 percent salt solution. Cut thin leaf samples, placing them on a glass slide. Add a drop of the salt solution, drying the excess on the slide's borders with a paper towel and cover with a cover slip. Explain what you see, writing down your hypotheses. Remove the cover slip, add distilled water to the sample and observe again under the microscope.