Peter, who lived 200 years ago, had a house with no rats in it. One day, his wife heard some scurrying around on his straw roof. He went up and guess what he
found? A rat's nest. Peter was really smart--where did he think the new rats came
from? Well 200 years ago, people believed that part of the straw roof somehow
turned into rats. Why would Peter, even though he was very intelligent, accept this
idea?
We're all really smart, but its not like we're the smartest people in the world. We all know that it takes a momma rat and daddy rat to make some baby rats.
This is because we understand something called the cell theory, because the cell theory is just part of our culture now. It's something a lot of our behaviors and
other ideas are based.
1. All living things are made of cells
2. Cells come from other cells
3. Cells are the smallest unit of life

1. Using two parts of the cell theory, explain to Peter why these two parts show
that the straw roof did not turn into the rats.
2. What do we mean when we say 'The cell is the smallest unit of life? Explain as if
you were talking to Peter, who has no idea about cells.