Calculate the diploid chromosome number of the hybrid offspring from a sheep and a goat.
Outline why the classification of sheep and goats indicates that hybridisation between them is unlikely to happen.
A cross between a white hornless goat and a bezoar horned goat gave offspring with four distinct phenotypes. Draw a genetic diagram to display the genotypes of the two parents, their gametes and the genotypes and phenotypes of the offspring.
Horns on farm animals such as goats and cattle can pose a risk to the farmer and to other animals. Horn growth is often stopped in 5-day-old animals by a stressful process called disbudding. Genetic modification can create a deletion in the allele $h$ coding for horns in cattle embryos, so that the allele no longer codes for a functional protein and the embryos develop into hornless cattle. State an ethical advantage of this example of genetic modification.
Suggest why genetic modification that causes a deletion in the horned allele, in established breeds of dairy cattle, is preferable to selective breeding for hornless animals.