With the beginning of the middle proterozoic comes the first evidence of oxgen build up in the atmosphere. with is catastrophe came eukaryotic forms. these include multicellular algae, and toward the end of the proterozoic the first animals
Respiratory system, because the lungs and diaphragm would get the oxygen from the air, and transfer them to the circulatory system (that's a pretty basic explanation, there's much more to it)
5 atoms 2 iron and 3 oxygen I hope this helps
You can reduce the levels of matter pollution by reducing the amount of particulate matter produced through smoke and by reducing vehicle emissions. Reduce the amount of particulate matter produced through any types of smoke.
Answer:
I think that it is Eukaryotes
Explanation:
