well, that is an easy question,
evolution, yes the very same that started are life, lungs, the same as us,
animals were here before us, yet we evolved with greater intelligence,
(if you are with a religion and you say humans were here first don't criticize me i am a scientist, not a freakin' pope)
There are too many animals on Earth to list here. Maybe you could limit them to particular species?
They look like normal animals here on earth but sometimes can be mixed up.
Close to 100%. Plants, whether on land or sea, generate the oxygen that animals need to breathe. Some bacteria, for example, are anaerobic - that is, they do not take in oxygen. But most likely, the organic stuff that anaerobic bacteria eat at one time depended on plants to live (or might even be a plant.
some animals would not be living here!
well dogs are one but a lot of animals can get bloat seeing that we only discovered a portion of life here on earth
Yes they are very important. If animals weren't here on earth , the human body would basically become extinct . Therefore, we need our animals to survive.
People can only breathe on Earth because the atmosphere here contains the right amount of oxygen needed for human respiration. Other planets may have atmospheres with different compositions that do not support human life.
Plants take the carbon dioxide that animals breath and turn it into oxygen, which animals need to survive. If there were no plants we couldn't live here.
to keep the plants green. we woud not be here on earth without it because we need it to survive, and the animals too. ;)
if you talking about where do 'WE' get the animals? well we get them from forests, grasslands, jungels, deserts, etc. we sometimes use them for food so we can obviously live but we also get them to train them put them in the zoo and even pet them. ( which means we keep them as pets.) BUT, if your talking about how did they come onto earth and like if we didnt put them here then who and what did? well people say god created the earth in 7 days. that he put the nature wildlife water and sea creatures in it and everything else, that's how the animals came here. but if you do not believe in god, how the animals came here is the question. animals bread with the opposite sex which makes more babies, but how did the animals before them and before them & before them get here? that's the question!
The carbon atoms that are already here are recycled. When plants and animals die, all the elements they have are recycled and reused.
because ok high altitudes