Elodea leaf under microscope
Elodea in tap water vs salt water
Students in high school should know that a eukaryotic cell is a highly organized entity made up of many subcellular components. These subcellular components are specialized parts that each perform a specific role that is required for the cell’s survival. The majority of these structures are difficult to see in living cells due to their small size and colorlessness.
In this lesson, students will use a microscope to look for chloroplasts, cell walls, and cell membranes in Elodea, a popular aquarium plant. Students would then investigate the impact of various salt solutions on the cell structures of Elodea plants. Students will observe the process of plasmolysis, or the shrinkage of the cell contents due to water loss, by adding salt water to the Elodea cell environment. However, rather than focusing on terminology, you should concentrate on what happens during plasmolysis. Students can gain an operational understanding of plasmolysis as well as strengthen their understanding of osmosis and diffusion by conducting this lab. According to research, students can find it easier to comprehend that the cell is the basic unit of structure (which they can see) than that the cell is the basic unit of operation (which has to be inferred from experiments). (p. 342, Benchmarks for Science Literacy.) It’s necessary to remember that cellular processes affect the whole organism. By the end of eighth grade, students should understand that all of an organism’s basic functions are carried out within cells, and that the way cells function is identical in all living organisms. (P. 112 of Benchmarks for Science Literacy.) Students can also understand how to use a microscope.
Elodea leaf under microscope
The chloroplasts can be seen flowing around the cell in the videos due to a process known as cytoplasmic streaming, in which the cytoplasm flows around the nucleus. It also flows around the vacuole (despite the fact that the vacuole itself isn’t visible in the videos). The cell wall and mitochondria are visible in the predicted images, in addition to the cytoplasm, chloroplasts, and nuclei. At this magnification, the plasma membrane is too small to see. The mitochondria aren’t apparent in the printed picture that the students are working with.
Elodea cells are about 0.05 millimeters long (50 micrometers long) and 0.025 millimeters wide in size (25 micrometers wide). Since the shapes of the cells differ to some extent (as seen in the image), taking an average of three cell dimensions, or even the results from the entire class, gives a more reliable estimate of “typical” Elodea cell size.
Episode 1: elodea wet mount
The “wicking” technique is used to draw a solution over a slide specimen. The solution is drawn or “wicked” over the specimen by putting a piece of tissue or paper towel at one edge (right) and dropping the solution at the other edge (left).
After soaking the slide in salt solution, this image shows plasmolyzed Elodea. The chloroplasts have all clumped together in the centre. This shows how living cells react to a hypertonic solution.
This image depicts Elodea in its natural state. Both before and after the distilled water is placed on the slide, the chloroplasts are spread throughout the cell. While distilled water is a hypotonic solution, the cell wall prevents the cells from bursting.
Elodea under the microscope
The images below show the Intel Play QX3 Computer Microscope’s output with and without an ordered cone of illumination from a substage condenser with an aperture diaphragm. High magnification views of a thin section of Elodea leaf tip stained with a quadruple stain consisting of safranin O (nuclei, chromosomes, and cell walls stain red), fast green (cytoplasm stains green), crystal violet (starch stains blue/purple), and orange G (nuclei, chromosomes, and cell walls stain red), fast green (cytoplasm stains green), crystal violet (starch The photomicrographs were taken with a 200x objective and are meant to show cell and leaf growth. In the lower photomicrograph, you can see how a substage condenser is used to arrange the illuminating light rays. In the absence of a condenser (upper image), specimen detail is completely lost.
Elodea is a form of underwater plant native to North and South America that was once common in aquariums. Unfortunately, since their development is nearly uncontrollable, some of these plants have been dumped into lakes and ponds in non-native regions around the world and have become nuisance organisms. The plants form dense mats that suffocate native aquatic plants, degrade fish habitat, and obstruct aquatic sports.