CHROMOSOMAL MUTATION:
Chromosome mutations are unpredictable changes that occur inside chromosomes. These changes are brought during meiosis or by mutagens (chemicals, radiation, ultraviolet rays, etc). This mutation can result in changes in the number of chromosomes in a cell or alter the structure of a chromosome. Chromosome mutations change and impact on the entire chromosome; as opposed to genetic mutations, which alter a single gene or larger segment of DNA on a chromosome.
A diagram on the types of chromosomal mutations and how its shape is altered.