If they say that all human cells replace themselves every 7 years or so, why can scars remain on your body for the entire life?
In:
The cells get replaced by being ‘copied’ so when mistakes are made/created they are also copied.
This why/how ageing happens, mistakes in the system of copying and reproducing the cell are retained.
It’s a very complex system so it’s amazing it works properly at all. The minimal mistakes that happen are not surprising.
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