A Labrador retriever breeder needs to determine if three male pups who were born to Sadie, his black Labrador retriever, are the offspring of Sam, a yellow Labrador retriever from another breeder. Which process could the breeder use to determine if Sam is the father of the pups?

STR analysis compares short repeated DNA regions inherited from both parents. By comparing the pups’ STR patterns with Sadie’s and Sam’s, the breeder can check whether the pups have inherited DNA variants from Sam. Mitochondrial DNA is generally passed through the mother, so it cannot establish paternity; Y-chromosome analysis alone is less informative, and PCR is a technique for copying DNA rather than a paternity test by itself.

AI-written and checked against the verified answer.