There are three important points to keep clear in the relationship between sex and heredity. Sex-limited Traits Refer to traits that are found only in one sex.
Egg production is limited to females.
There are other obvious sex-limited characters that I will leave to your curiosity. Sex-influenced Traits refer to traits that are expressed in both sexes but the mode of expression is different in one sex. Pattern Baldness is the classic example where the trait or gene is dominant in males and recessive in females. Sex-linked Traits refer to traits that are on the same chromosomes as the sex determining genes. In 1910 Thomas H. Morgan found a white eyed fly that exhibited a very interesting pattern of inheritance in reciprocal crosses .