Final answer:
A molecule that possesses both hydrophilic and hydrophobic qualities is known as an amphipathic molecule, such as a phospholipid, which forms the core structure of cell membranes.
Step-by-step explanation:
A molecule that is both hydrophilic and hydrophobic is called an amphipathic molecule. An example of such a molecule is a phospholipid, which has a hydrophilic "head" and a hydrophobic "tail". The hydrophilic head of a phospholipid is attracted to water and is made up of a phosphate-containing group attached to a glycerol molecule, while the hydrophobic tail, consisting of either saturated or unsaturated fatty acids, repels water. This dual nature allows phospholipids to form the structural foundation of cell membranes, creating a barrier that controls the entrance and exit of substances.