What is defined as a change in the DNA sequence of an organism?

A change in the DNA sequence of an organism is referred to as a mutation. Mutations can occur in various forms, such as substitutions, insertions, or deletions of nucleotides in the DNA strand, and they can have a range of effects on the organism, from harmless variations to significant impacts that can lead to genetic disorders or influence traits.

Mutations are important in the study of genetics, evolution, and various biological processes because they contribute to the genetic diversity of populations and can be a driving force behind natural selection. This is distinct from concepts like genome, which refers to the complete set of genetic material in an organism; recombinant DNA, which involves artificially combining DNA from different sources; and polymorphism, which typically refers to the existence of two or more alleles at a locus in a population, rather than a change in DNA sequence.