Biogeochemical Cycles (DP IB Environmental Systems & Societies (ESS): HL): Exam Questions

Part of the carbon cycle is shown in the diagram below.

Identify processes X and Y in the diagram.

Describe how carbon is released during process Y.

Carbon from fossil fuels enters the atmosphere during combustion.

Explain how this process contributes to rising average global temperatures.

Cutting down trees during deforestation increases the problem described in part a.

Explain how.

Describe the role of bacteria in the nitrogen cycle.

The figure below shows a diagram of a stream that runs past a farm.

A group of students took water samples at various locations along the stream and measured the nitrate concentration in parts per million (ppm) in those water samples.

The students have marked these nitrate concentrations on their diagram.

Explain how the farm may be causing the increase in nitrate concentration in the water.

Explain why methane is considered a potent greenhouse gas.

Describe the role of nitrifying and denitrifying bacteria in the nitrogen cycle.

Outline the process of ammonification in ecosystems.

Explain how reef-building organisms contribute to carbon storage.

Distinguish between the processes of nitrogen fixation and nitrification.

Explain how different components of the carbon cycle act as stores, sinks or sources.

Discuss how managing carbon stores and sinks contributes to climate change mitigation.

Discuss how human activities affect the nitrogen cycle and the impacts of this on ecosystems.

Explain the role of bacteria in shaping nitrogen flows in the nitrogen cycle.