Botany Week 7

This week, the lesson was on photosynthesis.  The last time I taught botany, I was worried about it because I had never really understood what photosynthesis was, but as I studied it, I began to find it really interesting, even miraculous.  I still can't claim to fully understand it, but as I prepared for this class, I learned a little more and if they ask me to teach it again, maybe I can add a little more.  It is a complicated, amazing thing and there is no way more than a very basic understanding can be taught to this age group anyway.

Because of my new motto "I'm never sorry I did it early", weeks ago, I made a very large poster board leaf with two layers glued together.  The bottom was not glued down and could be opened to reveal a cross section of the leaf and the bottom layer of stomata -the tiny mouth like holes on the bottom of leaves.

I made smaller paper leaves to match for the students, which they glued the same way to a page for their lab books.  After leading them to add the cross section parts and the stomata, we began to talk about this formula:

Carbon Dioxide + Water + Sunlight = Sugar + Oxygen + Water

All of the children knew that plants and animals exchange air and most of them had at least heard of photosynthesis and chlorophyll.  They each had 6 small arrows to match my 6 larger arrows and we labeled each one for the parts of the above formula and glued them in the part of the leaf where they enter or leave it.

Most of the kids had no understanding of the chemical nature of anything beyond knowing H2O means water and that molecules are small.  I had a printed copy this:

Not so much to teach them what it meant, but to show them that the sugar molecule is so much bigger and more complicated than the water, oxygen, or carbon dioxide - and on the chance that a kid or two would know more about it and would find it interesting.

To further illustrate the chemical nature of photosynthesis, I brought a handful of Legos and quickly assembled a "building" and then broke them apart and built an odd shape.  I hoped to let them understand that plants take one thing, break it into pieces and build something totally different.  I am not sure they understood.

What I do think they understood is that leaves make a kind of sugar to feed the plant.  And since most of them didn't know that before the beginning of class, I think it was a success!

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At the end of my class, one of the administrators (they call it"the committee" - so a committee member, but actually the one most in charge) came to my class to talk to the kids about our fire drills.  It was a good chance for me to stand in the back of the room and watch someone else instruct this particular group of kids.  She did it masterfully and I was glad to see it!  I hope I can learn from her.  It did encourage me that  when I saw her later she laughed about what a talkative group they are!