The sum of all external conditions that affect a person is referred to as

Recessive traits are less common than dominant traits because usually

A) both parents must have the same recessive trait in order for it to be inherited.. B) both parents must either have the recessive trait or be a carrier in order for it to be inherited. C) recessive genes are more sensitive to the crossing-over process than dominant genes. D) only fathers are able to pass on recessive genes to their female offspring.

Gender Identity Disorders almost always begins in:

a) Childhood b) Adolescence c) Early adulthood d) Middle age