Human impact and conservationIB MYP Sciences: Mind map

Exam questions on Human impact and conservation

1. In Borneo, a large area of tropical rainforest has been cleared so that palm oil plantations can be planted. Conservation scientists are recording what happens to the local ecosystem over the following ten years.
   Explain why the population of orang-utans in the area is likely to fall after the forest is cleared.2 marks
2. Cane toads were brought to north-eastern Australia in 1935 to eat beetles that damaged sugar cane crops. The toads spread rapidly across the north of the country. They produce a poison, and native predators such as quolls that eat them often die.
   Explain how the cane toads could cause the numbers of native species such as quolls to fall.2 marks
3. A class in a school near Lake Victoria wants to find out how fertiliser run-off from farms affects a pond. They add different amounts of nitrate fertiliser to five identical tanks, each containing 2 dm³ of pond water. The tanks are kept in the same sunny window, and the students measure the percentage of the water surface covered by algae after 14 days.
   State the independent variable, the dependent variable and one control variable in this investigation.3 marks