Modeling Radial Holoblastic Cleavage
| Autor: | Linda K. Ellis |
|---|---|
| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | The American Biology Teacher. 62:362-364 |
| ISSN: | 1938-4211 0002-7685 |
| Popis: | This laboratory activity, designed for an undergraduate course in developmental biology and suitable for AP Biology, is a direct result of El Nino. Less than 24 hours before the scheduled arrival of living sea urchins from California in January of 1998, we received a call telling us that 17-foot seas had prevented their collection ... maybe we could have them next week! Facing a three-hour lab period, I was prompted to take advantage of the time to try something that I had thought about, but had not found time during lecture to do: to make some of the embryological processes more concrete by making and/or using 3D models. A quick trip to Toys "A"' Us provided the Play-Doh" (I have since discovered Crayola'sT? "Model Magic"O which is also a good material to use). I had skewers and plastic bags at home, so we were ready to go. I was a bit skeptical about the reaction my junior and senior biology majors would have when they saw the Play-DohT", but they were politely enthusiastic. On observing them during the activity, they seemed to be having a good time. After allowing the smell of Play-Doh" to resurrect preschool memories, there was a lot of discussion about how to proceed, especially as the cells grew more numerous and the divisions more complicated. The students worked it out cooperatively, often setting up an assembly line type of approach. Throughout the semester, we came across additional concepts that were difficult for them to think about in three dimensions. One example is the fates of the cells in the frog blastula. Having memorized a diagram showing the dorsal lip on the right hand side of the embryo, they were unable to transpose the facts they had learned to a drawing showing the dorsal lip in the center of the embryo. Several students suggested that we should have made a big model, like we did for cleavage. Rotating the model could help them think of it threedimensionally. |
| Databáze: | OpenAIRE |
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