Differentiate between population density and population distribution

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

You see a white marker with an orange circle and black lettering. what does this marker tell you

Which feature of a human community is similar to a niche in a biological community