Explain the principle by which genetic fingerprinting can identify the father of a panda cub.

• A. All bands in cub that do not come from the mother must be present in the father's fingerprint
• B. The father always shares all bands with cub
• C. The cub's bands are independent of parents
• D. The mother's bands determine the father's genotype

Answer: (A)

Genetic fingerprinting relies on one allele passed from each parent to the offspring, so the cub’s DNA pattern is a mix of maternal and paternal bands. By comparing the cub’s profile to the mother’s, any bands that appear in the cub but are not found in the mother must have come from the father. Those paternal bands must be present in the father’s fingerprint, which lets you identify the father. In practice, using several loci strengthens the conclusion, since some bands can be shared between parents and still be informative only when viewed across multiple markers. The other ideas aren’t correct because the cub’s bands are not independent of parental DNA, you can’t deduce the father’s genotype from the mother alone, and the father does not have to share all bands with the cub.