How is the sea of electrons model is used to explain the physical properties of metals? electrons give off a charge, the greater or lesser the metal will depend on how packed the universe is in the metal, atoms and such.
Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural  even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair.
Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down.This is not necessarily unnatural  even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair. DNA fails to copy accurately. 2  Most of the mutations that we think matter to evolution are naturally-occurring.. 3  For example, when a cell divides, it makes a copy of its DNA  and sometimes the copy is not quite perfect. 4  That small difference from the original DNA sequence is a mutation.