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Cells | ||
| Issue | Naive Idea* | Scientific Idea |
|---|---|---|
| Static vs dynamic | Cells are static structures. | Cells are dynamic hotbeds of metabolic activity. |
| Interphase | Cells are resting when they are not dividing. | Cells are most metabolically active during interphase, the period between cell divisions. They are typically engaged in biosynthesis and growth during this time. |
| Respiration | Respiration occurs in the lungs and is solely the process of gas exchange. | Respiration has two stages - gas exchange which occurs in lungs, gills, or stomata, and biochemical changes that occur in the cells (cellular respiration). |
| Cellular Respiration | Cellular respiration is characteristic of animal cells but not plant cells. Plant cells photosynthesize instead. | All eukaryotic cells capture energy from the breakdown of sugars via cellular respiration in the mitochondria. |
| Nutrients | Plant and animal cells obtain their nutrients (food) from the environment. | Plant cells have the unique capacity to synthesize their own nutrient building blocks, 6-carbon sugar molecules, from inorganic substances such as CO2 and H2O. All other organisms and their cells must take in organic molecules derived directly or indirectly from plants. |
| Diffusion | Everything a cell needs gets into it by diffusion. | Only the smallest molecules such as H2O, CO2, and O2 can diffuse freely into and out of cells. Larger more charged molecules such as sugar and salt ions require active transport across the membrane. |
* A misconception or alternative idea has three primary features: it is a cognitive idea that differs in a significant way from the scientific idea, it is held by a sizable proportion of the population, and it is notably resistant to being taught away; it is often described as a conceptual primitive (Clement, 1982). There are many other types of errors in understanding besides misconceptions (Fisher & Lipson, 1986).
Anderson, C.W. & Others, (1986). The Effects of Instruction on College Nonmajorsı Conceptions of Respiration and Photosynthesis. Eric Document 270 317.
Fisher, K. M. & Lipson, J. I. (1986). Twenty questions about student errors. Journal of Research in Science Teaching, 23 (9), 783-803.
Songer, C.J. & Mintzes, J.J. (1994). Understanding cellular respiration: An analysis of conceptual change in college biology. Journal of Research in Science Teaching. 31 (6), 621-637.
