Wednesday, November 30, 2011

Plant Germination Experiment: Part III

This week in class we worked on writing the discussion section for the plant experiment.  Over the three weeks of this project, students set up the experiment, graphed the results (which coincided with graphing in Math) and now we discuss our results in a assignment that will be graded both in our science class and in their Literacy class. 

Students recognize that scientists need to be well rounded, and that the lessons they learn in their other classes like Math and Literacy, are fundamental to success in science.

Here is an example discussion a 7th grade student wrote in class:

“In this experiment we studied how salt in water can affect corn and radish germination. This was important to study because farmers depend on germination of their crops to live, and we depend on some crops to eat and get everything we need to survive. We set it up by putting 5 corn or radish seeds in a petri dish with water that has different amounts of salt. What happened was the radish seeds germinated faster than the corn. But nothing grew in the 3.5% salt dish and the 0.5% salt grew fastest. The 1% salt corn had all 5 seeds grow, the 1% radish had about 1 dead seed we think because the last day of this experiemnet one seed was covered in mold. The results mean salt can effect germination and too much can kill a plant, but I think a little salt might be good. I think I would try growing different plants with this experiment, maybe just corn and radishes are the only plants whose growth is affected by salt but maybe not”

Plant Germination Experiment: Part II

Students have collected data every other day on their plant germination rates for the last week.  Now we started graphing the data.  We decided to use line graphs, which coincides with the curriculum in Math Class.  They had learned how to do Line graphs earlier in the week, and now were able to apply their knowledge. Although we started graphing the data, there is still one more week of data to collect.  Every other day, student will check their experiment, and add data points to the graph.

Plant Germination! 10/28

We have been very busy in class recently.  We undertook a three week plant germination experiment.  Students wanted to see how salt influenced germination rates in two plant species that are used for human consumption.  Corn, which Iowans are very familiar with, and radish's.  There are many places around the world where salinity is a major problem for crop lands, and if lands aren't properly managed, soil can be inhospitable to crop growth.  Australia is a great example, as removing native vegetation and irrigating has drawn up salt from well below the soil.   We designed a simple experiment to see how different salinity levels influence germination, and to see if both species responded similarly.

Pictured here is our experiment.  Each petri dish has 5 seeds of radish or corn.  2 species x 4 treatments, replicated by 6 class periods.