The topic focuses on biodiversity and the wealth of natural resources used by humans. Why there are so many different species is considered first, with the concept of niche and adaptation explored. The topic looks at how all this diversity has come about through adaptation and natural selection and how this leads to evolution. The concerns for disappearing biodiversity and loss of potential natural resources are used to highlight the need for biologists to identify, name and classify species. The topic has sections on both traditional and novel uses of plants and plant fibres and the use of chemical extracts from animals and plants. The relationship of plant anatomy to function and the structure and role of cellulose and starch is studied. The topic ends with the issue of sustainability and the role of zoos and seed banks in conservation of endangered species.
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 investigation of the biodiversity of different habitats, investigation of taxonomic hierarchy using biological specimens, and examination of animal cells under the microscope and using electron micrographs.
Opportunities for developing mathematical skills within this topic include using ratios, fractions and percentages, calculating areas of circumferences and areas of circles and volumes of cylinders, substituting numerical values into algebric equations using appropriate units for physical quantities, solving algebraic equations and understanding the principle of sampling as applied to scientific data.