The correct answer is a dichotomous key. Basically, you use the key to decide what species an organism is by looking at what traits it has, and if it doesn't have some traits you can instantly rule out a large number of species which brings you closer to your answer of what the species is that you're looking at.
The environment is your correct answer<span />
Answer:
Structure and function of the cell membrane
The cell membrane is semipermeable (or selectively permeable). ... The unique structure of the cell membrane allows small substances (like oxygen or carbon dioxide) to easily pass through.
Explanation:
Ecosystems need producers because they are the start of the food chain.
Producers are consumed by first consumers, the second consumers and so on.
Answer:
I think it was Thomas Hunt Morgan