AYUDA

What kinds of molecules can pass through the cell membrane without any problem?

1. in what ways have non-native species been beneficial? 2. what are some of the hypotheses for the collapse of honeybee colonies? 3. distinguish between regional and functional extinction. 4. why is it difficult to measure background extinction rates? 5. what three factors are most important in causing extinction rates to climb?

Examine the following diagram. place the labeled layers in order from youngest to oldest.