The role of hydrophobic tail

The hydrophobic tails of phospholipids molecules play an important role in permeability of plasma membrane. State the role of hydrophobic tails. Predict what will happened if all hydrophobic tails failed to function.
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Hydrophobic tails are relevant to forming lipid bilayers of membranes in living cells. Membranes function as barriers to the external environment of cells, as well as allowing the cell to selectively import or export material across the membrane. As far as the hydrophobicity of the tail region of phospholipids, they are attracted to other hydrophobic tail regions and will spontaneously aggregate to form a bilayer because that is the most energetically stable configuration the amphipathic molecules can form (meaning the hydrophilic head groups will orient themselves in the same direction relative to their tail regions which also determine orientation).

Failure to function would not allow membrane formation - cells could not exists. (nor organelles or any other membrane bound compartment)