I Used to Hate Mold, But Now It’s Growing On Me

By: Sydney McGhie and Kelley Plasterer, Fourth Grade East Teachers
Fourth grade scientists study the cyclical nature of our natural world. Our big question of the year for science is: How can we make sense of problems in order to design multiple solutions? During our life cycles unit, students build ecosystem models and study how energy makes it from the sun, to our food, to us, and then back into the soil to start life over again.
In the main project for the unit, students were presented with the challenge of growing food in an enclosed ecosystem. Students created a design solution to growing food in a dome for two years, based off of the real experiment done in Arizona in 1991, the Biosphere 2 project. They were asked to observe what they see, think, and wonder about an ecosystem, which directed the content of each science class. 

Students’ questions and interests drive the exploration. They begin to recognize that pursuing answers to their questions gives them the opportunity to adapt or change the model they have thoughtfully designed. At the beginning, students were questioning how they could grow what they needed to make their favorite snacks - Takis, hamburgers, Cheetos, bacon, and all. As we learned more about food chains, and the ingredients needed, they were then tasked with making sure not only those ingredients were there, but that there was a sustainable environment for their ingredients to thrive. If it was a plant, did it have what it needed to make sugars from the sun? If it was an animal, did it have something to eat?  

Currently, students are experimenting with mold and different variables that either prevent or speed up the process of decomposing. In groups, students chose a household item they thought would prevent mold from growing on bread, cheese, an orange, an apple, and a french fry. Out of a variety of options, groups chose hot sauce, vinegar, salt, honey, and soy sauce as variables. This experiment pushes students to test a hypothesis, collect data, and interpret results. The students are equal parts excited and grossed out as they check on the process of mold every morning! 

As we learned about producers, consumers, and decomposers, we made sure to add each of these elements to our biodome ecosystem. While we are not finished just yet, students are currently exploring the questions that came up in class: How do we deal with the waste? What makes a food chain into a cycle? These questions came from the students’ research and exploration. Another amazing question that came from a student was: Could we say decomposers are the true apex predator, as it eventually consumes everything? We are wowed by our inquisitive ecologists.


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