sentence: All humans have some pheomelanin in their hair.
sentences_before: Pheomelanin colors hair red. Eumelanin determines the darkness of the hair color. A low concentration of brown eumelanin results in blond hair, but more brown eumelanin will color the hair brown. High amounts of black eumelanin result in black hair, while low concentrations give gray hair.
concept_name: human
headings: Hair Human hair Hair color Genetics and chemistry
categories: Basic English 850 words