| A | B |
|---|
| host | the organism harmed by a parasite |
| hazardous waste | substances that are very harmful to humans and other organisms |
| succession | the process of gradual change from one community of organisms to another |
| parasite | an organism that lives on or in another organism |
| competition | When two or more species must use the same limited resources |
| extinct | when an entire species is gone forever |
| endangered | when a population drop below a certain number and is close to extinction |
| fossils | evidence that shows how species have changed over the years |
