This is possible because proteins are created from different combinations of amino-acids. While we only have 20 different kinds of aminoacids, these 20 kinds can create thousands of combinations that we can observe in our bodies and bodies of other mammals as well as other organisms.
ANSWER:
Its because mother nature tells us herself!
its just like predicting when rhinos will go instinct:
imagine people killing 2 rhinos a week or every two weeks and theres only 500-1000, you can predict that in prob 3-5 years they'll go instinct
so its just like that and they have much higher technology now that it'll just give them the answer without putting much effort into it.
~batmans wife dun dun dun....
Any eating utensil that you can find
it takes place in the eukaryotic and prokaryotic cells.
in eukaryotes cell, it occurs in the matrix of the mitochondrion.
as you consider this, to me the answer is matrix