Earlobe type is PHENOTYPE, that is coded by a person's GENOTYPE.
The genotype refers to a team of genes in a person that is responsible for the expression of a particular trait. For instance, a genotype is responsible for the height of a person, whether the person is short or tall depends on the particular genotype that controls the height trait. Phenotype refers to the physical characteristics or physical manifestations of a particular trait. For instance, tallness is a phenotype, it is a physical expression of the genotype that controls height. In the same way, earlobe type is a phenotype that is determined by a person's genotype.