Gene mutation

• Natural selection results in species that are better adapted to suit their changing environment through the process of evolution
• Genetic diversity increases the reproductive success of a species as it survives long enough to be able to breed and pass on the advantageous allele
• Genetic diversity arises from mutations in DNA and recombination of genes
• Substitution mutation replaces a base in a DNA sequence with another base
• Deletion mutation removes one of the bases from a DNA sequence causing a frameshift
• Addition mutation adds a base to the DNA sequence
• Chromosome mutations are changes in the structure or number of chromosomes
• Changes in the whole sets of chromosomes occur when organisms have three or more sets of chromosomes rather than the regular two
• Non-disjunction is the failure of homologous chromosomes to separate properly during meiosis, usually resulting in one more or one fewer chromosomes