persistent changes in the genome that can be passed on to the descendants of a given cell or organism. Mutations play a fundamental role in the development of living organisms, being the main source of genetic diversity and the driving force of the evolutionary process. They can both contribute to the adaptation of organisms to the environment and lead to various hereditary diseases. Mutations are classified according to the nature of changes in genetic material into three main groups:
1) Gene (point) mutations. These are changes that occur in the structure of the DNA molecule. Examples of diseases: phenylketonuria, albinism.
2) Chromosomal mutations. They are associated with changes in the structure of chromosomes: loss (shortage) – loss of the end part of the chromosome, deletion – loss of a section of the middle part of the chromosome, duplication – doubling of a chromosome fragment, inversion – rotation of a chromosome region by 180°, translocation – transfer of a section of one chromosome to another. Consequences: severe forms of mental retardation, blood diseases, decreased viability, leukemia.
3) Genomic mutations. They are associated with a change in the number of chromosomes: polyploidy – a multiple increase in the haploid set of chromosomes (triploidy (3n), tetraploidy (4n), hexaploidy (6n)); Aneuploidy (heteroploidy) is a non-multiple change in the number of chromosomes (2n±1, 2n±2).