This topic builds an appreciation that photosynthesis is the primary process that underpins the majority of ecosystems, and provides students with an understanding of how ecosystems work. The topic continues by looking at whether climate change will lead to extinction of species or evolution by natural selection, and looks at the evidence for climate change and its effects on plants and animals. By the end of the topic students should appreciate how scientific understanding can make us aware of our responsibilities as stewards of the environment.
Students should be encouraged to carry out a range of practical experiments related to this topic in order to develop their practical skills. In addition to the core practicals detailed below possible experiments include investigating food webs in a habitat, and investigation of the effect of changing carbon dioxide levels on temperature.
Opportunities for developing mathematical skills within this topic include recognising and using expressions in decimal and standard form, making estimates of the results of calculations, using ratios, fractions and percentages , using a scatter diagram to identify a correlation between two variables, plotting two variables from experimental data, drawing and using the slope of a tangent to a curve as a measurement of rate of change, calculating rate of change from a graph showing a linear relationship, determining the slope and intercepts of a linear graph, solve algebraic equations, change the subject of an equation, understand the principles of sampling as applied to scientific data, and using a statistical test.