What does a DNA molecule look like with a mutation?

Answer 1

A mutation is a change in the sequence of nucleotides that make up DNA. Changes can cause a change in phenotype when they change a gene or regulatory sequence, but can be silent mutations when a stretch of so called 'junk DNA' is affected.

A mutation can be either a spontaneous occurrence or induced by environmental factors such as free radicals / ionising radiation.

Mutation is considered to be the driving force behind evolution, regardless of where it all originates from: evolution (change) through mutation is a fact.

Answer 2

It doesn't alter the structure at all. It alters the sequence, either by substituting one or more nucleotides(the A's, G's, C's and T's that make up the sequence of DNA) with another nucleotide, or by adding or removing nucleotides.

The structure of the protein encoded by this DNA sequence(if any, < 2% of the human genome is translated... that is, encodes proteins) can be adversely effected, as a change in the genome sequence will confer a change in the amino acid sequence of the protein, conferring a change in conformation(however the risk of this is somewhat mitigated by the redundancy in the genetic code), or in some extreme cases, substituting a single nucleotide can introduce a STOP codon(a sequence of 3 nucleotides that signals the end of translation... that is, the protein stops being made before it is completed).

Answer 3

The A-T & C-G chain would not be properly in order if there was a mutation. In other words, a DNA molecule with a mutation looks ugly.