Ionic bonds result when electrons are tranfered between atoms. Covalent bonds result when valence electrons are shared between atoms. You should be able to identify whether an ionic or covalent bond is being formed between atoms.
The lists of the correct order of evolutionary history is Jellyfish, Reptiles, Mammals. This three are classified as vertebrates and all I know that almost all the animals we know are vertebrates. Jellyfish is a fish that do not have a backbones, example of reptiles is garter snake, there are so many mammals in the forest such as bat, rodent, bear and much more.
The polluted bacteria and algae interacts with fish and other aquatic wildlife, so they will be negatively impacted by that relationship in this case.
