I had a lab today where the 6th graders were looking for protists in this soup of decaying leaves, dirt, and water that had been "brewing" since Sunday. Each day I added a little flour and pulled out a dropper of the liquid and observed a slide full of swirling little single celled monsters. This morning at 7 I set up a slide and at least 30 unicellular bumper cars careened in front of the lens. I decided to put the beaker outside and let it heat up a bit. At 10:30 I brought the beaker inside and separated the "protists soup" into four beakers for each student team. By 11 a.m. the 6th graders were dropping their own drops of the "soup" onto a slide and NOTHING!! Where had the little monters gone? We struggled to find a few paramecium stragglers and each kid at least said they saw one. I'm not sure anyone believed me when I swore that just 4 hours earlier one drop of the liquid would have had 20-40 protists dashing and darting all over the slide.
Great question today from an 8th grader after I explained why viruses were not considered alive by many scientists. She asked, "So what's their purpose?" I countered, "What's our purpose?" The whole class started thinking. It was close to the end of the class. I started telling them about how some scientists theorize that the evolution of our cell types evolved from an archae cell that was invaded by a virus. The hope or belief of some cosmic purpose to each organism for some reason thrills me.
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