What term refers to a change in the DNA sequence of an organism?

The term that refers to a change in the DNA sequence of an organism is mutation. Mutations can occur naturally during DNA replication or be induced by environmental factors, and they can affect a single nucleotide (point mutations) or larger segments of DNA. These changes can have various effects on the organism, including no effect at all, a beneficial change, or a harmful alteration.

In contrast, replication is the process by which DNA is copied to produce two identical copies before cell division; it does not inherently involve changes to the DNA sequence itself. Transcription is the process by which the information in a DNA sequence is used to synthesize RNA, which is a separate process and does not involve changing the DNA sequence. Inversion specifically refers to a type of mutation where a segment of DNA is reversed within the chromosome, but it is just one form of mutation rather than the definition of the broader concept. Therefore, mutation encompasses all types of changes to the DNA sequence.