Last week I introduced a group of young people to a new world of wonder. It has been a short time since I noticed doing that, but in reality I have enjoyed a lifetime of “new world” introductions. You see, I spent the majority of my life (so far,) as a biology teacher. Though I retired from the high school classroom 4 years ago, I still teach. Sometimes I teach groups of students that visit the Lake Metroparks Environmental Learning Center (that is in Lake County in northern Ohio.) Sometimes I teach my granddaughter Maddie, and sometimes I simply teach people that happen to be standing next to me. But this week I was reminded of how exciting it can be to learn too. I work with a group of third through fifth grade honors or gifted students from a local school district. I guess they are “gifted” because they have been tested and identified as “cognitively gifted,” but I think they are gifted because they show up every Tuesday afternoon, after a full day of school, with notebook in one hand, snack in one hand, camera in one hand, and usually some other artifact in one hand. They accomplish this because they are third through fifth graders, they have an almost unmeasureable amount of energy, they are gifted, AND they are curious!! This week I gave them access to the microscope. This week I gave them access to new worlds. Their energy, and their curiosity did not disappoint. I decided to start their adventure with some microscope basics. I wanted them to appreciate how special this exploration tool is. I wanted their journey to be less frustrating and more successful. I wanted them to be able to see and to measure with the microscope. They were ready, willing and very able to explore new worlds. The world I introduced them to was an import from my small, backyard pond. As I left for the Environmental Learning Center I stopped and collected a bagful of pond water and a few handfuls of hair-like filamentous algae. The major genera in my pond is *Cladophora. (Sometimes called “pond scum,” but I prefer Cladophora.) My favorite thing to see in pond samples is, in fact the alga types. I love the green color and the ability to see into the cellular landscape. I love seeing the intercellular spaces and the dots of color in the chloroplasts. I love trying to “notice” the nucleus in the cell. I say “notice” because that is what you do when you start a journey into the microscopic world. Often the new adventurer will fail to notice what is clearly there. “Can I get a new sample?” “There isn’t anything in mine!”. I go over to take a look at this “empty” field of view. “Wow!” I scream. “Look at this!”. I tend to “notice” more stuff. Of course I see the algae. I describe the cellular boundaries, the cell walls, the membrane, the chloroplasts, the nucleus (if lucky and the lighting just right.) Then I look beyond the strands of algae and “notice” the hundreds or thousands of euglena scooting around the filaments. They are small. We have the 10X objective employed, but visible if only you are willing to “notice.” occasionally a much bigger paramecium swims by. I go crazy! By this time the young explorer wants her microscope back. They want to “notice” what’s on the slide too. New worlds, new wonders! Then we load up the slide with some daphnia. Daphnia is what these scientists want. They are big enough to be easily observed.
They are complex enough to look like real pond monsters. Daphnia are small microscopic crustaceans. They have a heart, gills, a digestive system, an eye spot AND they are “see-through.”. Perfect for a young scientist to get excited by this new world. They can see something happening. Thirty-four years teaching biology, four years of undergrad biology classes, two classes of biology in high school, and I still get goofy when I see a captured daphnia on it’s side, heart pumping, gills waving, food moving through the intestines, living its little life on the microscope slide for all to see.
No wonder the mini-explorers get so excited! As a special treat , we gave each of the little scientists their very own “daphnia-in-a-tube” to wear on a string around their neck and to take home. Their own new world, their own new wonder!
*Recently a discovery of a new use for this pesky pond clogger has been made. This web site discusses a possible use of the cellulose abundance of Cladophora. They may be harvested for use in new, efficient , paper batteries. They can come to my pond and harvest all they want. Check out this site. http://ceramics.org/ceramictechtoday/materials-innovations/green-algae-harnessed-to-make-paper-based-batteries/
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Location:Misty Ridge Dr,Painesville,United States