3) What can cross-breeding and inbreeding experiments tell us, and what can’t they tell us?

Cross-breeding used to be used to figure out how closely related two species are. Since the invention of molecular techniques, they have been used less and less often. That is because molecular techniques are more precise, more informative and they take much less time to perform than breeding experiments. Breeding experiments can still inform us whether a particular trait, such as albinism, is controlled by a single gene or multiple genes, whether it is sex-linked, and whether it is recessive or dominant.