On Friday, January 3, 14 hardy girls (and four boys, including my four-year-old son!) braved the cold and snow to travel to the Chicago Botanic Garden and learn more about photosynthesis. On the way there, Program Manager Krystal Meisel challenged them to learn—or review—as much about photosynthesis as they could, either from each other, from the chaperones, or by texting or calling a friend.
When we arrived, CBG volunteers led a review of photosynthesis and the group aced all their questions. Then they explained the basics of cellular respiration, when plants use up stored food they’ve made through photosynthesis. Knowing that plants make food when sunlight is available, the youth were invited to hypothesize whether plants in the garden greenhouse would be photosynthesizing food or using up stored food through cellular respiration.
Inside the garden, the students formed teams and used probes to measure the amounts of oxygen and carbon dioxide the plants were releasing overtime. The teams captured clear readings of decreasing amounts of oxygen, showing that the plants were using up stored food, not making new food.
In a second activity, the students put plant cell samples from a desert plant and a rainforest plant under a microscope to find and count the stomata in each. They found that the jade plant had fewer stomata because it needs to conserve water more than the rainforest plant does.
After lunch the group took time to explore the Winter Wonderland model train exhibit. This was my son’s favorite part, and the older kids enjoyed it too.
“Before I came, I didn’t know anything about photosynthesis,” said 6th-grader Eryn W. “I’m going to remember it’s how we get oxygen.”