1. CELLS AND THEIR ENVIRONMENT HOMEOSTASIS anddiffusion

2. LIFE’S BALANCING ACT If you are too hot or too cold your body temperature is out of balance

4. Sweating and shivering are the body’s response to extreme temperature. They help the body return to a temperature that is comfortable. The body is balanced

5. CELL BALANCE Your body is made up of cells. And, just like your body, cells must stay balanced. They must have just the right amount of materials to maintain the proper environment for your body.

6. HOMEOSTASIS The balance that all living things have to maintain, is called HOMEOSTASIS.

7. INTRODUCING DIFFUSION

9. The movement of particles in our cells, from areas that are crowded to areas that are less crowded, is called DIFFUSION crowdedless crowded

10. Remember the cell? How many of these parts do you remember? nucleus ???? mitochondria ???? cytoplasm ???? Cell membrane ???? Diffusion happens in cells.

11. This is one of five channels in the diagram that move particles in and out This is a cell membrane. Can you find the parts where particles might go in and out of the cell? Click to check your answer.

12. Think of the cell membrane like the doors of a school. Students go in and out only through the doors.

13. Students are like the particles in cell diffusion. They move from the crowded buses into the school through the doors. Once inside they spread out pretty evenly into their classrooms.