Which phrase best describes definition diffusion

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

What causes the phospholipids to organize themselves the way they do

Consider the classification levels of a human. eukarya ,animalia ,chordata ,mammalia ,primates, hominidae ,homo ,sapiens .which is the most specific taxonomic level in the classification system above? a sapiens b homo c hominidae d primates