Individuality of DNA

[Fortissimo]

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.

[Paralith]

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.

[Fortissimo]

Thanks. You cleared that up really nicely.