Why do phospholipids tend to spontaneously orient themselves into something resembling a membrane?

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

Acell goes through cellular respiration and produces atp which it then uses to move a molecule across the cell membrane. how does the energy in the original glucose molecule change during this process? (2 points)

24. how are vaccines used to keep people healthy?