What three conditions favor red tide?

How many trophic levels are there in the following food chain? phytoplankton - shrimp - perch - pike - osprey

How did the research presented in the article affect scientists' understanding of the evolution of eukaryotes

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food