Why are wilderness hard to measure?

What pattern of migration do whales follow?

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

Is dna the same in every cell in the human body explain your answer