Justify controls and baselines, evaluate sampling, variability and ethics, and suggest measurable extensions that improve validity in unfamiliar investigations.
The photograph shows a young locust eating the leaves of a plant.
Locusts can breed in large numbers and destroy crops, such as sorghum, in East Africa. A scientist observed that some varieties of sorghum were more likely to be eaten by young locusts. The scientist collected the seeds of two varieties of sorghum (A and B) and grew them in trays. Locust eggs were collected and hatched into young locusts. Twenty young locusts were placed in a cage containing 100 g of fresh sorghum leaves of variety A. The cage was kept at . After 24 hours, the leaves were removed and the mass of leaves eaten was calculated. This method was repeated with fresh sorghum leaves of variety B. The method was repeated six times for these two varieties of sorghum leaves. The results: Mass of leaves eaten of variety A 17.317.217.517.016.716.9 Mass of leaves eaten of variety B 17.817.917.717.617.817.4
Describe how the student could extend this investigation to collect more data to either support or reject the hypothesis.