2. F UNCTIONS AND D IVISION OF C ELLS By: Madison Paige Regan, Lizzie Oleary, Erin McDonald, Jeffrey Pfeiffer

3. T ODAY ’ S T OPIC Functions and Divisions of Cells Diffusion Osmosis Division of Cells Mitosis Characteristics of Cancer Cells

4. D IFFUSION The moving of a substance from a higher area of concentration to a lower area of concentration Diffusion happens because the particles are moving constantly Many substances are allowed to pass through a cell membrane by diffusion Oxygen, water, and carbon dioxide – CAN Salts, proteins – CANNOT

5. B EFORE DIFFUSION AFTER DIFFUSION

6. O SMOSIS Diffusion of water throughout a cell membrane. Although water molecules are polar they are small enough to pass through the membrane freely. This special case of diffusion that involves the movement of water molecules across a membrane is called osmosis.

7. O SMOSIS IS DEFINED BEST AS ? A) Water molecules across a membrane from an area of high water concentration to an area of lower concentration B) Molecules from an area of low concentration to an area of high concentration C) Water molecules in a container Tap board to reveal the correct answer. A) Water molecules across a membrane from an area of high water concentration to an area of lower concentration

8. D IVISION OF C ELLS When single – celled organisms get too large they divide into two organisms. As the cells divide into two multicellular organisms grow.

9. M ITOSIS Is the process in which the cell nucleus divides 1. Nucleus contains DNA, a material that holds coded information about the organism. 2. When mitosis begins, DNA forms chromosomes which carry information about the cells activities.

10. D O YOU THINK YOU CAN NAME ALL THE CHARACTERISTICS OF A C ANCER C ELL ?

11. C HARACTERISTICS OF C ANCER C ELLS 1. Cell growth is uncontrolled 2. Cells do not function as part of the body 3. Cells take up space and interfere with normal body functions 4. Cells travel throughout the body 5. Cells produce tumors and abnormal growths

12. T HE E ND !