Currently, in 7th grade, we are learning all about cells! We have used microscopes to look at and diagram what cells looks like magnified. Now we are investigating some of the essential parts of cells, starting with the cell membrane.
We have read that cell membranes let water and other small molecules pass in and out. Each pair of students are going to design their own investigation to see how much of a change happens when cells are placed in different solutions. To do this we are using chicken eggs, with their shells removed.
When you soak an egg in vinegar, the vinegar dissolves the calcium carbonate of the shell, slowly leaving only the egg's membrane as its outer barrier. Now we will see what happens when we put these eggs in tap water, colored water, salted water, and liquid solutions of their own devising.
As this two-week long project is happening, students will be learning about the other major organelles of both plant and animal cells. To demonstrate their understanding they will build models of these cells out of edible materials. They will use these models to help them identify organelles, and explain their functions.
The 7th grade curriculum has students become interpreters of living systems. We focus on three essential questions: (1) What is a living organism? (2) How is my body like a machine? (3) How can I think and behave like a scientist?