State the age group which had the highest incidence of dengue fever in 2012.

Estimate the mean incidence rate of dengue fever for all years in the 20–24 age group.

Outline one strategy used to limit the spread of a water-borne disease.

Explain how using genetically modified organisms (GMOs) to increase food production can lead to one environmental disadvantage.

Explain how using genetically modified organisms (GMOs) to increase food production can lead to one social disadvantage.

55–59

6.2 (allow 6 to 6.4)

Award [1] for the strategy and a further [1] for development/explanation.

For example, only use safe (boiled/bottled) water [1], to ensure that disease is not transmitted by drinking potentially infected water [1].

Award [1] for a valid disadvantage and up to [2] for further development / exemplification.

For example: potential loss of biodiversity/ depletion of wildlife [1] due to the extensive use of herbicides to cultivate GMOs [1] for example, the use of glyphosate/RoundUp as an herbicide could cause the decline of the monarch butterfly [1].

Other possible environmental disadvantages include:

• pressure on water resources/ depletion of groundwater supplies, due to need for irrigation for GMOs
• decrease in resilience to issues such as drought and insect infestation; due to lack of bio-diversity in GMO crops
• the “out-crossing” of GM crops with wild relatives, and the potential to create new weeds.

Award [1] for a valid disadvantage, and up to [2] for further development/exemplification.

For example: population health issues [1] GMOs may increase resistance to anti-biotics [1], due to the manipulation of genes in a laboratory environment [1].

Other possible social disadvantages include:

• possible increased risk of cancer; because the disease is caused by mutations in DNA, it is dangerous to introduce new genes into the body
• rise in inequality between rich and poor farmers, as poor are unable to afford high cost of inputs required by GMOs
• debt reduces farmers spending on health/education as farmers borrow money for high input costs of GMOs (seeds/fertilizer/irrigation) so have to cut back elsewhere.

No problems in reading the graph.

No problems in reading the graph.

This was well done with many correct answers identifying ways of limiting the spread of cholera and other water-borne diseases. Some were confused with dengue and malaria and incorrectly answered regarding these diseases.

Knowledge of GMO crops was poor, superficial, and often incorrect. Often there were contradictory answers or generic unsupported assertions such as 'they cause disease'. Very few gained full marks for either environmental or social disadvantage.