species is an inherited characteristic & genes are able to determine the inherited characteristics of a living thing ->  genes are able to determine the species of a living thing  a snake is a kind of animal & a lizard is a kind of animal & different kinds of animal belong to different type of species & toad is a kind of animal ->  toad, snake, and lizard are different species  genes are able to determine the species of a living thing & toad, snake, and lizard are different species -> the genes of toad, snake, and lizard determine their species