Two differences of multicellular organisms having some specialized cells rather them all the cells being the same

The influenza virus cause the flu, but not other diseases. why?

As a result of these processes the single celled organism accomplishes

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?