Thursday, November 19, 2015
10:00 - 11:00; 60 min.
Science:
Bio-accumulation food chain -
Today we used beakers, an eye -dropper, and food coloring, to explore how energy moves through the food chain. First I had Samantha make labels for each of the actors in the food chain; producers, first level consumers, second level consumers, and decomposers. We then filled each beaker with 20 ml of water, for each label. Samantha was tasked with placing 3 drops of food coloring in the producer beaker to represent the energy plants convert from sunlight. She then took a dropper and placed as many drops from the producer beaker to get the first level consumer beaker to be the same color as the producer beaker. When we got to 120 drops, and the colors were not the same, we stopped. I asked Samantha how many plants a caterpillar would have to eat to get the same amount of energy the plant requires. We then moved to the second level consumer and again stopped after 120 drops. The color was not even close to the first two. Again Samantha was asked how many caterpillars would a bird have to eat, to get the energy one caterpillar can get from eating a bush. We discussed how fewer animals populate each level of the food pyramid. I showed her a pyramid that described the food chain in an ocean habitat, a forest habitat and a desert habitat. We then discussed what would happen if the plants were sprayed with a pollutant. And a caterpillar would eat the 120 plants, getting 120 times more pollutant. The birds would eat 400 caterpillars, and get 400 x 120 times the pollutant than the single plant. Homework: read Xeroxed pages about the food chain. Study the vocabulary words highlighted, and draw a 2D food pyramid for a habitat of her choice; Due upon her return from Thanksgiving vacation.