Cell Experiments & Activities

Cells are the smallest, most basic functional units that comprise living organisms. They are made up of smaller structures called organelles, which carry out different cell functions (for example, the mitochondria are responsible for respiration). Some ideas for cell science projects and activities include experimenting with salt and cell cytoplasm, examining cell nucleus and genome size, and extracting DNA from plant and animal cells.


All living cells have cytoplasm, which is a fluid-like substance (sometimes referred to as protoplasm) that cell bodies---such as mitochondria and ribosomes---float around in. In plant cells, the cytoplasm is contained both by an inner cell membrane, and an outer cell wall. As an experiment, you can observe the effect salt has on plant cell cytoplasm, assuming---of course---that it can penetrate the cell wall and membrane. According to crystal-clear-science-projects.com, you will need to take a small tissue sample from an onion and examine it under a compound microscope (100x magnification will be sufficient). You can then saturate your sample with a five percent solution of salt in water, observe, and do the same with a 10 percent solution. You may discover that the salt dissolves the cytoplasm of the cells in your onion, allowing you to have a better glimpse at the inner-workings of the plant cell.


Every species of animal stores DNA in the nuclei of its cells. However, some store more DNA than others, which correlates to a larger genome size. According to sciencebuddies.org, genome size is determined by weighing DNA, and is measured in picograms (one picogram equals one trillionth of a gram). For this experiment, you will determine if there is a correlation between the size of animal genomes and the size of their cell nuclei. To do this, you will need to utilize the Cell Size Database, which lists the genome sizes and nuclei sizes (measured in μm2, or in millionths of a square meter) of different animals. You will likely want to organize your results according to animal kingdom (for example, have a section for amphibians, mammals, etc.) and make a chart and/or graph to display them.


This experiment will require equipment and chemicals that you may only be able to access at a high school or---perhaps more likely---university or college laboratory. According to usc.edu, your goal will be to determine if it is easier to extract DNA from an animal cell as opposed to a plant cell (which, as mentioned earlier, features a sturdy cell wall). You will need to take samples of animals and plants, such as small bits of chicken liver or onion, and prep them for extraction. This requires adding a buffering solution, a detergent and a neutralizing solution to each sample, and then subjecting each to a centrifuge (which rotates fluids at extremely high speeds). Finally, you need to add isopropanol to isolate and extract the DNA. For an additional twist on the experiment, treat plant samples with cellulase---which will breakdown cell walls---and see what effect this has on extraction.