Aging takes place because as time passes copy errors pile up in our DNA and the quality of our cell decreases. Is that correct? If yes why is the DNA of children brand new. Their DNA is born by combining the DNA of the mother and father both of which usually have DNA of average age. Why does the combination process give birth to shiny new DNA? Why are the errors acquired by both parents by the age of 20 or 30 discarded.

Aressera said:

Because mutations don't occur in the vast majority of cells. There are also error-correcting mechanisms (e.g. apoptosis) that will reduce the impact of mutations on the organism. So, as long as the sperm and egg cells that created a child are un-mutated, then the child will not have any mutations.

what I understand is that the child aquires new genes regardless of how old his parents were when the pregnancy started.

I have another question. When stem cells become specialized cells how does each cell know the type it should become? Like the cell that is to become the liver should be located in the middle of the right side of the body. The cell located at the top extremity can’t become a liver etc.

Thanks for sharing Aressera, interesting facts.