Final answer:
In a phospholipid, the hydrocarbon tail is hydrophobic, meaning it repels water. Phospholipids are amphipathic, with hydrophilic heads and hydrophobic tails, important for cell membrane structure. so, option 2 is the correct answer.
Step-by-step explanation:
In a phospholipid, the hydrocarbon tail is hydrophobic with regards to water. This means that the tail, which is composed of two fatty acids, is water-fearing and cannot interact with water. Phospholipids are amphipathic molecules, meaning they have both a hydrophilic and a hydrophobic part. The hydrophilic part is the polar head that contains the phosphate group. In contrast, the hydrophobic hydrocarbon tails are nonpolar and repel water. The amphipathic nature of phospholipids is crucial for the formation of cell membranes, where the hydrophilic heads face the aqueous environment and the hydrophobic tails face inward, away from water.
A phospholipid is an amphipathic molecule, meaning it has a hydrophobic and a hydrophilic part. The fatty acid chains are hydrophobic and cannot interact with water, whereas the phosphate-containing group is hydrophilic and interacts with water. This combination of hydrophobic and hydrophilic regions allows phospholipids to form the lipid bilayer of cell membranes.