What types of mutations do you know and what is their biological and practical significance?

Types of mutations (by the nature of changes in genetic material): genomic, gene, chromosomal.
Genomic: polyploidy, heteroploidy (monosomy, trisomy, polysomy).
Gene (point): replacement of a pair of nucleotides, insertion of a new pair (shift of the reading frame), loss of a pair of nucleotides.
Chromosomal: inversion, duplication, deletion, translocation, centric fusion.
There are other classifications of mutations. For example: nuclear and cytoplasmic, neutral, useful and harmful, somatic and generative.

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