Virtuаl Lаb - Micrоscоpy – Plаnt Cells (Oniоn Epidermal Cells) The following image is of another plant, called Elodea, which has visible chloroplasts (the tiny, small green circles in each rectangular cell). One of the cellular activities that can be observed with a live specimen is cytoplasmic streaming. Cytoplasmic streaming is the movement of the cytoplasm within particular kinds of cells, like these Elodea cells. As the cytoskeleton directs the cytoplasm to flow, nutrients created from the chloroplasts, macromolecules and organelles are circulated and distributed throughout the cell. For more practice, calculate the estimated width (in
Virtuаl Lаb - Micrоscоpy – Plаnt Cells (Oniоn Epidermal Cells)All living systems are made up of either prokaryotic or eukaryotic cells. Bacteria are prokaryotic organisms. Prokaryotic cells are generally smaller, less complex, and most importantly, the genetic material (DNA) is not enclosed in a membrane-bound structure (known as the nucleus). All bacteria are prokaryotes. Eukaryotic cells make up all the other kingdoms of life: plants, animals, fungi, and protists. Eukaryotic cells are generally larger, more complex in cellular organization, and have distinct membrane-bound structures known as organelles (including having a nucleus). Most cellular structures are too small and colorless to be visually identifiable using a light microscope. However, it is possible to visualize nuclei in eukaryotic cells using a light microscope. In this next simulation, you will observe onion epidermal cells, which are harvested from the inner portion of a layer from an onion bulb. The bulb of the onion grows underground so, therefore, the organelle which accomplishes photosynthesis, the chloroplast, will not be visible in an onion bulb. Furthermore, since most cellular structures are colorless, it is important to treat many kinds of cells with some kind of stain before observing them with a light microscope. The color contrast the stain provides allows better observation of cellular detail and activity.