- Anonymous1 decade agoFavorite Answer
Okay...long story short.
Females, I believe are X chromosomes, and males are Y chromosomes.
When conceived, the male's sperm carries X and Y chromosomes to the egg, which are always X chromosomes.
If a sperm carrying an X chromosome (aka: Xx) to the egg conceives, the baby will be a girl. If a sperm carrying the Y chromosome conceives (Xy), the baby will be a boy.
Notice the consistency...all EGGS are female...so nipples are a given either way...it just depends upon the X or Y chromosome from the father on whether the hormones know to grow in the future, or stay flat in the future.
Hope this helps.
- lancer92Lv 41 decade ago
it only shows that they are also mammals.