Why does magma form at mid-ocean ridges?

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity

In pea plants, yellow seed color (y) is dominant and green seed color (y) is recessive. based on the punnett squares, what are the chances that the offspring in the second generation will have green seeds? first generation y y y yy yy y yy yy second generation y y y yy yy y yy yy there is a % chance that the offspring will have green seeds.