1. The human machine is organized at different levels, starting with the cell and ending with the entire ______
2. At each higher level of organization, there is a greater degree of _______________.
3. Many human cells are specialized in form and _________________.
4. Muscle cells have many __________________ that provide the energy they need to move the body.
5. After the cell, the _________ is the next level of organization in the human body.
6. _________ tissue protects the body and its internal organs.
7. Epithelial tissue secretes substances such as _______.
8. Nervous tissue makes up the brain and the _______________ that connect the brain to all parts of the body.
9. Human organs are organized into organ systems.
10. The _________ system takes in oxygen and releases waste gases.
11. The skeletal system provides ___________________ to the body and protects internal organs.
12. Functioning together, the organ systems keep _______________, pH, and other conditions at just the right levels to support life processes.