If the dominant allele is t and the recessive allele ("non-taster") is n, than tn and tt are the genotypes of a "taster". tn is heterozygous and tt is dominant homozygous. nn is the genotype of a "non-taster" and it is recessive homozygous.
The removal of the cell membrane.
The membrane regulates homeostasis by letting "stuff" (general term) in and out of the cell.
