Science

We have continued our study of ecosystems and energy in ecosystems. Students explored food chains with a game called "Predator In Training", where groups compete to get all of the components of a food chain and then put the organisms in the proper order. We expanded each individual food chain from a different habitat into a more complex food web with multiple producers, prey and predators. 

Lately, we have been more focused on producers (plants) and their role in capturing the sun's energy and turning it into sugar. We discussed the different parts of plants that we eat, which transitioned well into making a delicious pumpkin soup for harvest festival! Yum!

We also explored the different colored pigments that leaves have in them that help trap the sun's energy by separating the pigments into reds, greens and yellows. Students compared leaves from different plants as well as leaves of different colors (test strips before separation are below).

This last week, we explored the different starch content of foods by dripping iodine onto pieces of apple, banana, bread, crackers and a drop of honey. Iodine turns dark in color in the presence of starch - we found the banana to be most surprising in that it takes a few minutes to develop a dark color but not uniformly. It was especially fun to test the difference between mashed and chewed crackers. Students were expecting that both would be starchy, but we found that there was less starch in the chewed crackers. Students were quick to realize that this meant that something in our mouths was changing the starch, but what? (It turns out we have an enzyme in saliva that works quickly to break down starch into sugar). 

In engineering challenges, the students built towers using only classroom supplies (markers, rulers, etc) that were at least 45cm tall, were free standing and could hold an apple at the top of them. The third/fourth graders surprised me by how quickly some groups achieved success with this challenge!

Pigment from spinach and mint to be separated.

The moment as the apple was placed...

Measuring for height (not quite 45 cm yet).