As a biology teacher I've often found it very difficult to get students interested in the botany section of our curriculum. Truth be told, I find it difficult to get myself interested in the botany section of the curriculum. Though I'm not quite sure why this is the case. Without plants life does not exist. The interplay between our waste being their life and their waste being our life is fascinating. Not to mention the fact that they provide the most exquisite examples of coevolution in action. Plants come in a rainbow of colors, act as the base of almost all food chains, grow nearly everywhere, can live to the ripe old age of 5000, produce toxins the kill quickly and lifesaving drugs, actively hunt insects, and so much more. Yet the barely receive a second glance. As is the case with some many good things, its likely we just take them for granted.
Application seems to be the best strategy I've found for helping students give plants a chance. Rather than just talk about the fact that plants carry out both photosynthesis and respiration, we do a lab that measures the impact of some variable on respiration. Instead of theorizing regarding the impacts of humidity or wind on rates of respiration, we design experiments to test the impact of environmental conditions on waterloss. And instead of leaving thoughts of plant defense mechanisms out in the nebulous ether, we interact with the crazy world of botanical adaptation through the BBC series, Life.
I may not have produced any future botanists, but hopefully this approach has helped the citizens of AP Bio appreciate the foundation of the living world just a bit more. Ramya Mulugu and Michelle Polanco fill this week's reporter spots. Each took a few minutes to reflect on the work that we've done.
During the week of Jan. 26 – Jan 30, we had the opportunity to complete our next lab, with seeds of mung, barley, and of course, the historic pea; our training ground. We were charged with designing an experiment that would discover the rate of respiration of the germinating seeds, with glass marbles as the control. Changing either temperature, pressure, or volume, we could calculate the rate of change, and in AP Biology, it is well known that an unchanging dependent variable is as common as Mr. Kite giving us pathogenic E.coli to do a lab on, i.e, not common at all.
The original experiment involved peas placed in 4 different vials; in order to act as control, glass beads were used. This experiment measured the effect of temperature on the rate of respiration. We used two water baths, one at room temperature and another at 10 C. 25 germinating peas were put in one vial, and to match, the same volume of non germinating peas and glass marbles were put in another vial; this was repeated for the other bucket too. Respirometers, which measure respiration stopped off each vial, then each was partially submerged in the water. We discovered that temperature did have a significant effect on respiration rate, and next, we were charged to design our own experiment. My partner and I decided to change the peas to barley and maintain temperature as our independent variable. One thing I noticed about using barley was that it tends to be longer than peas, and based on some of the literature I have read, there may be a correlation between seed size and germination, but that’s another question for another day. I also discovered the scientific use of petroleum jelly to safeguard the stopping reputation of respirometers, and though our hands were forcibly moisturized, the experiment ran smoothly. The barley proved the relationship between temperature and respiration, with slightly higher results than the peas.
Application has been on our lists this year as the crucial component of everything we do. In the case of my experiment, I recognized the ramifications of cellular respiration on the crops that we consume, especially grain, which is a type of grass. It is a fruitless endeavor to regulate Mother Nature, but proper planting practices based on biological principles can mean the difference between the bread basket of the United States, and the barren wasteland of the same.
Just as every other week in AP Bio, we had our daily quizzes along with notes. On a more interesting note, on Wednesday we watched a movie on plants and on Thursday we began a new lab. The movie focused on the different defense mechanisms plants have acquired and how they use them. The plant I found most interesting was the Venus flytrap, which are native to North Carolina. A slight touch on one of its trigger hairs is enough for the plant to close and smother the predator to death. From another aspect, the creation of the film was interesting to see. It takes an immense amount of time and money to produce this type of film. Overall, the film helped build a connection between what we were learning in class to the real world. It's one thing to talk about these different defense mechanism, but another to see them in action. The second most interesting thing of the week was the lab we started on Thursday. It focused on the transpiration rate of plants. For my groups experiment, we decided to test the effect of wind. Unfortunately, I was not in class on Friday to find out the results. This concludes my recount of this week in AP Bio.