What term describes disruption of endogenous genes caused by the integration of a transgene into the genome?

• A. Sequential disruption
• B. Transgenetic modification
• C. Insertional mutation
• D. Integrational insertion

Answer: (C)

Disruption of endogenous genes caused by inserting a transgene into the genome is described as insertional mutation. When the transgene lands inside a native gene or its regulatory regions, it can interrupt coding sequences, splice sites, or promoter elements, altering or abolishing the gene’s normal function. This insertional event is a mutagenic effect specifically from the integrated DNA. The other terms don’t capture this mechanism: there isn’t a standard concept called sequential disruption or integrational insertion, and transgenetic modification is a broader term for making genetic changes, not the specific disruption caused by integration.