I was wondering........DNA is touted as being the master substance to identify idividuals but it has a variance of only FOUR different components, C G A and T. How does this get arranged so that every individual organism has a different arrangement.

 

Secondly the genetic code is degenerate, yes? But is there any other advantage of this besides that any effect of a mutation is ameliorated?

 

Thanks people.

Fortissimo, in one human genome there are 3.2 billion base pairs of DNA. What is four to the 3.2 billionth power? It's a lot.

 

When they say that DNA is degenerate, that means that when it comes to DNA sequences that code for proteins, different 3-bp sequences code for different amino acids, but though there are 64 possible 3-bp combinations, there are only 20 amino acids - so for each amino acid there are a few 3-bp combinations that code for it. So amino acid protein sequences are less diverse than DNA sequences. Which is why DNA is better for typing individuals.

Thanks. You cleared that up really nicely.