Fill in the blanks: In humans, some traits, such as freckles…

Fill in the blanks: In humans, some traits, such as freckles, cleft chin, and widow’s peak are the result of simple dominant-recessive inheritance, in which there are _______ alleles for each trait. (Type a number). Other traits, like skin color and height are the the result of the type of inheritance called _______ inheritance. But most human traits, including intelligence, body weight, and susceptibility to disease, are probably influenced by both heredity and _______ .