Six Names, One Problem
- Nutrition: get food into the body and break it small enough to use
- Transportation: carry it to every cell, because a cell cannot fetch its own
- Respiration: release the energy inside the cell, where it is needed
- Excretion: remove what would otherwise poison the cell that made it
Presenter notes: Start with something that sounds easy and is not. Ask the class to tell you the difference between a bus and a buffalo. Both move, both take in fuel, both give off waste, both get hot, both wear out. Take every answer and do not settle it. Two answers actually work and most classes miss them: a buffalo grows from the inside, and a buffalo can make another buffalo. Hold that back if nobody says it, because you will use it later. Then set the real question of the period: what is a body actually doing, all day, that a machine is not?