They are dangerous to the environment because they have no natural competition. That being said they have nothing to keep their population in check, therefore, taking away food, and habits from all the other species. Thus, causing species to die out, which in turn ruins the food chain.
Answer 1: A. Basic
Answer 2: 1. Cell
Answer 3: O. Organ
Hopefully this helps!! (:
I think it’s because you have trouble breathing
