Agriculture and food productionIB MYP Biology: Mind map

Exam questions on Agriculture and food production

1. Rice farmers in the Mekong Delta in Vietnam add nitrogen-rich fertiliser to their fields to increase their yields. After heavy rain, water draining from the fields carries some of the fertiliser into a nearby lake.
   Describe how the fertiliser entering the lake could lead to the death of fish.2 marks
2. Students at a school in Dubai compared two ways of growing lettuce. They sowed 10 seedlings of the same variety in soil and 10 in a hydroponic system, where the roots sit in a solution of mineral nutrients. Both groups were grown in the same room under identical lamps at 22 °C for 28 days. The students then weighed all of the lettuces. The mean mass of a lettuce grown in soil was 42 g and the mean mass of a lettuce grown hydroponically was 61 g.
   Calculate the percentage increase in mean mass of the hydroponic lettuces compared with the lettuces grown in soil. Give your answer to the nearest whole number.2 marks
3. A large farm in Kenya grows only maize, in fields covering hundreds of hectares. Stem-borer caterpillars have damaged the crop. The farmer sprayed insecticide, but the spray also killed bees and ladybirds, and a few months later the caterpillars returned in large numbers. A neighbouring farm instead releases parasitic wasps whose larvae feed inside stem-borer caterpillars.
   Explain why the caterpillars returned in large numbers after the insecticide was sprayed.3 marks