Did You Know Plants Make Their Own Food?

The other day I was out for a bicycle ride with my daughter when, out of the blue, she asked me if I knew that plants made their own food. I told her I did know that, and I asked her if she knew how they did it. She told me that they take air in through their leaves and use it to make “a kind of sugar stuff.”

My first response was to be blown away, because the daughter in question is four years old (she’d want me to say four-and-a-half, but who’s counting?). My second response was to ask her where she learned this. She told me, “It wasn’t from Magic Schoolbus,” which of course means she saw it on an episode of Magic Schoolbus. My third response was to fall into thought as we finished our ride. What I was thinking about what was this: the only difference between her explanation and one I might have given is that I would have used the word “photosynthesis,” and I would have mentioned that the plants take in carbon dioxide and give out oxygen.

I like to think of myself as a pretty well-educated and well-rounded person, yet when it comes to photosynthesis, that biochemical process so important that it is taught in-depth in both high school and college biology courses, I know as much about it as my four-year-old. Granted, the last time I took a biology class was more than 20 years ago, but since she hasn’t taken one at all I think she has me beat.

The obvious question is this: at this point in my life, how much should I know about photosynthesis? Put in a more subjective way, why is it that I don’t remember very much about this thing that was so important in class twenty years ago, yet I’m still able to be a productive member of society? Could we have spent less time on photosynthesis in high school biology to achieve the same outcome, and if so, what might we have done with that extra time?

Of course, I recognize that perhaps my teacher’s goal was not to for me to have life-long mastery of photosynthesis, but rather to develop certain life-long skills or habits of mind through my learning about photosynthesis. I think that there are topics we teach in every discipline that are used less for the content than they are as a tool for teaching a skill or mindset. But what I don’t think we do is make explicit for our students when the goal is the content and when the goal is a skill or mindset.

I’m going to try a couple of things this year to try to make this distinction more clear for my students. First, I’m planning to put some posters up on the walls that list the critical skills and habits of mind that students should be developing or employing, including some of the thinking moves described in Making Thinking Visible. Second, I’m planning to be up-front with my students about which concepts they need to remember long-term and which concepts they can forget about once we’re through using them, and I’ll explain why in both cases. My goal isn’t to have them remember what the graph of the sine function looks like twenty years from now, but if my approach helps them focus in on the things they need to remember for the next few years then it will have been a successful effort.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s