1. A Community of Cells How cells make up a body.

2. Cell Organization Cells are organized into systems that, together, perform functions that keep the organs healthy and alive.

3. Cells A cell is the basic building block on which the body is built on. The body is simply a collection of cells that do different jobs that live together in community.

4. Tissues Tissues: groups of similar cells that do the same sort of work Ex: Skin cells make up skin tissue

5. Organs and Organ Systems Organs: different types of tissues working together Organ systems: a group of organs working together to do a certain job.

7. Bone Cells are surrounded by a hard substance made of calcium and phosphorus

9. Nerve cells are long and have many branches. This allows them to receive and deliver messages quickly.

11. Muscle cells are usually long and have many fibers that can contract and relax.

13. Skin cells are mostly flat and close together. They form a protective layer for your body.

14. Read Section 15.3 Answer questions 1-5