After 10 generations of backcrossing, what is the resulting strain referred to?

The term used to describe a strain that has resulted from 10 generations of backcrossing is "congenic." Congenic strains are created by breeding a genetically modified or genetically unique animal into a particular inbred line. The backcrossing is done to introduce specific genes or traits while ensuring that most of the genetic background remains the same as that of the original strain. This process enhances uniformity in experimental subjects and minimizes variations that could arise from genetic differences.

In contrast, hybrid strains are typically produced by mating individuals from two different inbred strains, which would not involve backcrossing. Inbred strains are created through repeated sibling mating, resulting in a nearly homozygous genome and are not a product of backcrossing with another strain. Outbred strains are maintained without intentional inbreeding, resulting in higher genetic variability and are also not characterized by the backcrossing process. Therefore, the unique status of congenic strains makes this the correct answer in the context of the question.