They get energy by preforming chemical reactions within the cell
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.
Answer:
Excretion helps maintain Homeostasis by excreting wastes from the body, which eliminates harmful toxins housing themselves in your body, which would increase the chance of getting an illness. ... When you exhale, carbon dioxide and some water are removed from the body by the lungs.