February 16, 2023
What happens when you put a freshwater plant in salt water? The 9th-grade Biology students had an opportunity to find out. They are currently studying cellular transport, the movement of substances into and out of cells. They observed an elodea (freshwater plant) leaf under a microscope and were able to identify the individual cells border by the cell walls and the chloroplasts with their loads of green chlorophyll.
After observing and making drawings, the students applied a saltwater solution to the leaf on the slide and returned it to the microscope. Because the salt water has more solute than the inside of the plant cells, water moved out of the plant cells, causing the membranes to shrink away from the cell walls, clustering the organelles in a tight bunch, concentrating the chloroplasts with the green pigment into bright green dots.
Some students were lucky enough to spot some microorganisms from the aquarium flitting across their slides. Others could observe the brown, orange and yellow using them in the future. The pigments in parts of their leaf that had begun to die, the chlorophyll breaking down and allowing the other colors to be seen. The students enjoyed using the microscopes to view an entirely different world and will have more microscope fun in the future.