C. Immediately after mass extinction events D-50 million years after a background extinction event.
C. Is The Answer!
To show the different levels of classification and divide among species, and different organisms on planet Earth. It also creates a universal "language" for scientists around the world when referring to organisms (cougar & puma are the same animals; different name)
Example: The American Alligator and the Chinese Alligator (look it up!) are in the same family and genus, but are not the same species.
False in order for an ecosystem to survive there has to be some sort of competition. for example, if there were no sharks to eat little fish the little fish would over populate and then the little fish would run out of food which then means that whatever the little fish ate is now extinct and so on hinting the food chain's name. If it wasn't for competition nothing would survive
Answer:
The growth of the plants is the dependent variable, the stuff added to each plant is the independent variable, the plants that don't receive treatment/other stuff are control variables.