A lipid that has 3 long chains of fatty acids covalently attached or bonded to the glycerol backbone would form a single triglyceride molecule.
Stratum corneum is the answer
The phenotype is just a characteristic/trait.
For instance Brown and Green are phenotypes of eye color.
This can also be used in Punnet Squares, and could be displayed as B and G.
B equaling dominant Brown, and G = dominant Green, vice versa to g and b where they are recessive.