Immune system that is the answer to you question I think
Answer:
It is considered to be a scientific theory because,
Explanation:
there are many other believes or as you would call it religions that give a good explanation on how humans were created.
To be honest I don't believe the evolution because what if there was another way we were created, and not really turned into cavemen that came from monkey's or whatever.
It is honestly up to YOU on what you believe or feel about were we came from!
After DNA is duplicated it is called replication, it looks like this
The baby is used to getting what it needs through the placenta, which includes oxygen. The baby's lungs are initially filled with amniotic fluid.
