edu180atl: gary jones 8.16.11
Today, I learned a random but interesting science concept. While sitting in an impromptu junior high science department meeting, one of my science colleagues posed this question to the group: “why do trees lose their leaves in the fall”?
As it turns out, the decreased amount of sunlight in the late fall and winter decreases the amount of photosynthesis that takes place within the green leaves. As a result, not as much carbon dioxide (CO2) is converted into oxygen. The excess amounts of CO2 in the air trigger a chemical reaction with the chloroplasts in the leaves that ultimately rob the leaves of their vitality. This explanation contradicts the misconception that cold weather causes the leaves to fall. It just so happens that the decreased amount of sunlight is responsible for both the leaves falling and the colder weather, but these two effects are independent of each other.
That’s what I learned today! Now you may be wondering why a “science” teacher did not already know this. Well, my concentration is in physics. Life science is just as unfamiliar to me as French or Latin. So, this surprise “leaf” lesson was a pleasant one indeed!
About the author: Gary is a husband, father of three, science guy, and three-season coach. He really loves his students and enjoys teaching them life lessons in and out of the classroom.