In this lesson, I use pieces of wooden train track as a visual for students. Alternatively, you could use Legos or K'NEX to build a house, beads and pieces of string to create a necklace or a small puzzle. The purpose is to illustrate how to use the different pieces to go from single cell to a class "organism".
The manipulative aspect of this lesson is important for students to be able to develop a conceptual model to represent and understand the concept being taught (SP2).
To begin this lesson, I administer Page Keeley's "Human Body" probe (Keeley, Page. "Human Body." Uncovering Student Ideas in Life Science. (Arlington, VA: NSTA, 2011. 141-44. Print.).
The purpose of this probe is to identify students' thinking regarding the cellular makeup of the human body. I want to know if students recognize that the human body is an organized collection of cells (Herman's answer - everything is made of cells - student reply 1, student reply 2), and not cells inside "coverings" (Felix and Diandra's answers).
After students have finished their answers, I tell them to pile them up in the center of their tables since they might want to revisit them before turning them in at the end of the lesson.
I display the presentation.
As we go through the presentation, students use the wooden tracks to create a wooden train layout "organ system".
Slide 7: Each student gets a cell (piece of track).
Slide 11: In table groups, students join their individual pieces of track to form a "tissue". We discuss how this "tissue" can carry out the function of having a train go back and forth (but not all the way around).
Slide 16: Two or more table groups join their "tissues" to form an "organ" capable of performing the function of going all the way around.
Slide 19: Two or more "organs" are connected to each other in an "organ system".
The use of manipulatives to construct a physical model for students helps students understand how form is related to function and how different parts of a system work together (SP2). It, also serves the purpose of aiding the students in visualizing how a system works and how its function depends on the relationship between its parts. (CCC Systems and System Models - Systems may interact with other systems; they may have sub-systems and be a part of larger complex systems).
I tell students to gather their computers and navigate to Edmodo where I have posted a sheet for them to complete. The expectation is that they finish before the class period ends.
Note to Teachers: I have students create their own copy on their Google Drive and submit it electronically. If this is not an option for you, I have attached a printable copy.
This simple sorting exercise strengthens the physical model the students created by allowing them to develop the same concept of a system within known contexts - a human, a plant and a building (SP2).
To close the lesson, I ask the students to re-read what they wrote down at the beginning of the lesson. I ask them not to erase or cross out what they wrote originally, but rather to either add to it or write down a completely different answer in light of what they now know. I also mention that if they are satisfied with their original answer to write down 1 thing they learned, 1 thing that surprised them and 1 thing they are still wondering about.
I go over these sheets as a way to determine if the lesson was successful and to check the development of student thinking that every structure in an organism is composed of cells.