Our current science thematic unit is "Organisms." This year in grade 3 we are studying this unit in two parts. Part one, which we are studying now through November, focuses on classification and structures and functions. The essential questions for this part are: How are groups of organisms alike and different and how does this help us classify them?, Why do we classify organisms?, and How do the characteristics of organisms help them survive? Part two, which we will be studying in the spring focuses on life cycles. During that time we will hatch chicks and grow "Wisconsin Fast Plants" with our classroom grow labs. Our essential question for that part is How are organism life cycles the same and different?
One big aspect of helping students learn about classification is getting them to make careful observations of the world around them. We have each student keeping a Scientist's Notebook. One of the first entries in this notebook is a scientific drawing for which students collected an interesting plant and made a careful, detailed drawing including labels for the parts of the plants that they knew. While we did not expect students to know all the parts of the plant at this point, it was an exercise to help them begin to notice details about organisms and their structures, and how scientists and naturalists might use drawings of what they find to begin to identify them. Then students compared and contrasted stuffed animals using a Box and T-chart frame. Again, to help students begin to look carefully at features, but to also teach them how to use a specific comparison tool.
From there students began looking carefully at photographs of different animals and classifying them by creating their own categories that made sense to them ("furry animals," "animals with tails," and so on). Students were asked to record their categories for classifying the animal in their scientist's notebook. Our field trip to ECHO helped us with the next step in learning about classification. There we participated in a school program that focused on the specific features the five vertebrate classes have that scientists use to classify them. We have followed up by having students work in groups to record criteria for each of these five classes and then teaching other groups of students about them. They also worked on writing riddles in which they list features for a specific animal and by the end of the riddle they should have provided enough information for other students to "classify" them.
Our next step is to zoom in on specific characteristics of organisms and how these features or characteristics help them survive. We look at structures and functions of plant parts, and compare and contrast them to human structures. We study bird beaks and feet and what these features tell us about those particular birds and how they survive (what they eat, where they live). Students look closely at the organism they are studying in readers and writers workshop and determine what special features or characteristics that organism has to help it survive.
In the spring we will come back to organisms to compare and contrast similarities and differences between organisms' life cycles. To get a closer look at specific life cycles we will hatch chicks and grow "fast plants" in our classroom grow lab. This will be a great way to wrap up our year-long theme of "Growing, Moving, and Changing."