I believe that it is because when you put the hand on ice it causes the hand too cool and prevents/slows the rate at which the nerves get damaged.
The answer is , because one cell divides to form two identical cells.
In semiconservative DNA replication, each new double helix that will form will have 1 polynucleotide strand that is from the old DNA molecule and is an Old or Parent strand, and will have a polynucleotide strand from the newly synthesized one, the new DNA strand.
