Heredity influenced by sex

Some genes manifest differently for males or females. The action of male hormones causes the dominance relationship between pairs of alleles to change . Some alleles are dominant in one sex and recessive in the other.

For example, the allele of the gene responsible for baldness in humans is dominant in males and recessive in females.

Another example, the gene responsible for the existence of horns in some breeds of sheep is dominant in males and recessive in females.

Other examples of inheritance influenced by sex would be the presence of a white lock (dominant in males) or the length of the index finger shorter (dominant in males) than the ring finger.

Questions that have come out in University entrance exams (Selectividad, EBAU, EvAU)

Genetic problems solved: Heredity genetics problems influenced by sex (4th ESO). It contains genetic exercises that have come out in EvAU exams from various universities.