Agroup of cells working together make up a(n) organ system
molecule
organ
tissue

What are levels of ecology and how can we remember them

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?

Are humans interfering with or a part of evolution happening today? find examples of evolution seen in recent history that could be caused by human activity.