A native South African goat has an average daily milk yield of $0.25\,\text{kg}$. Calculate how many times larger the mean daily milk yield would be if that goat were replaced by the Northern European goat breed with the highest yield. Show your working and give your answer to two significant figures.
Explain how the data in Table 2.1 support the idea that some of the variation in goats' mean daily milk yield is caused by genetic factors.
The climate, vegetation and availability of veterinary care for goats in Northern Europe, Barbados and South Africa are not the same. Explain how Table 2.1 shows that environmental factors can lead to variation in goats' mean daily milk yield.
Native South African goats are more suited to local conditions in South Africa than a Northern European breed, such as the Saanen. However, Saanen goats have the potential to produce very large amounts of milk. Outline a selective breeding programme that could generate a goat with high milk yield that is adapted to the local conditions in South Africa.
Children in developing countries may drink unpasteurised goats' milk, and some may develop diarrhoea after ingesting live bacteria in the milk. Scientists have used genetic engineering to produce goats that make human lysozyme in their milk. Lysozyme is an enzyme that kills bacteria and therefore lowers the number of bacteria in the milk. State a social benefit and a social drawback of making these GM goats available in developing countries.