How is phospholipid bilayer arranged? and why does it arrange that way?

It arranges as 2 layers of phospholipids where the hydrophilic(water-loving) heads face toward the outside and the hydrophobic(water-hating) tails are on the inside. They arrange like this to allow for selective permeability which is why this is what a cell's plasma membrane is made up of.

A. mitochondrion b. nucleus

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