18. Biodiversity, classification and conservation

18.1 Classification

Learning outcomes

Candidates should be able to:

1. discuss the meaning of the term species, limited to the biological species concept, morphological species concept and ecological species concept

2. describe the classification of organisms into three domains: Archaea, Bacteria and Eukarya

3. state that Archaea and Bacteria are prokaryotes and that there are differences between them, limited to differences in membrane lipids, ribosomal RNA and composition of cell walls

4. describe the classification of organisms in the Eukarya domain into the taxonomic hierarchy of kingdom, phylum, class, order, family, genus and species

5. outline the characteristic features of the kingdoms Protoctista, Fungi, Plantae and Animalia

6. outline how viruses are classified, limited to the type of nucleic acid (RNA or DNA) and whether this is single stranded or double stranded

18.2 Biodiversity

Learning outcomes

Candidates should be able to:

1. define the terms ecosystem and niche

2. explain that biodiversity can be assessed at different levels, including:

• the number and range of different ecosystems and habitats

• the number of species and their relative abundance

• the genetic variation within each species

3. explain the importance of random sampling in determining the biodiversity of an area

4. describe and use suitable methods to assess the distribution and abundance of organisms in an area, limited to frame quadrats, line transects, belt transects and mark-release-recapture using the Lincoln index (the formula for the Lincoln index will be provided, as shown in the Mathematical requirements).

5. use Spearman’s rank correlation and Pearson’s linear correlation to analyse the relationships between two variables, including how biotic and abiotic factors affect the distribution and abundance of species (the formulae for these correlations will be provided, as shown in the Mathematical requirements)

6. use Simpson’s index of diversity (D) to calculate the biodiversity of an area, and state the significance of different values of D (the formula for Simpson’s index of diversity will be provided, as shown in the Mathematical requirements)

18.3 Conservation

Learning outcomes

Candidates should be able to:

1. explain why populations and species can become extinct as a result of:

• climate change

• competition

• hunting by humans

• degradation and loss of habitats

2. outline reasons for the need to maintain biodiversity

3. outline the roles of zoos, botanic gardens, conserved areas (including national parks and marine parks), ‘frozen zoos’ and seed banks, in the conservation of endangered species

4. describe methods of assisted reproduction used in the conservation of endangered mammals, limited to IVF, embryo transfer and surrogacy

5. explain reasons for controlling invasive alien species

6. outline the role in conservation of the International Union for the Conservation of Nature (IUCN) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)