What term describes an animal that has had a fragment of DNA introduced into its genome?

The term that describes an animal with a fragment of DNA introduced into its genome is "transgenic." Transgenic animals have had foreign DNA injected into their genetic material, which allows for the expression of new traits that are not inherently found in the species. This technique is widely used in genetic research, agriculture, and the production of pharmaceuticals.

In contrast, a chimera refers to an organism that contains cells from two different zygotes, meaning it has tissues from genetically distinct populations. A mutant is an organism that has undergone a mutation leading to a change in its DNA sequence, typically occurring naturally or through exposure to mutagens, rather than through the intentional introduction of foreign DNA. A hybrid generally refers to the offspring resulting from the mating of two different species or varieties, focusing more on the combination of existing genetic material rather than the insertion of new DNA.

Understanding the definition of "transgenic" is crucial in fields such as biomedical research and genetic engineering, where creating organisms with specific genetic modifications can lead to significant advancements and insights.