Assessing biodiversity (Edexcel A level Biology B)

This fully-resourced lesson describes how biodiversity can be assessed within a habitat at a species level and within a species at a genetic level. The engaging PowerPoint and accompanying resources have been primarily designed to cover point 3.3 (i) of the Edexcel A-level Biology B specification but as a lot of genetic content is covered when considering diversity within a species, this lesson can be used as an introduction to topic 8 material…

A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise key terms from their definitions. This quiz introduces species, population, biodiversity, allele, recessive and dominant and each of these terms is put into context once introduced. Once biodiversity has been revealed, the students will learn that they are expected to be able to assess the biodiversity within a habitat and within a species.
The variety of alleles in the gene pool of a population increases the genetic diversity so a number of examples are used to demonstrate how the number of phenotypes increases with the number of alleles at a locus. The CFTR gene is used to demonstrate how 2 alleles results in 2 different phenotypes and therefore genetic diversity. Moving forwards, students will discover that more than 2 alleles can be found at a locus and they are challenged to work out genotypes and phenotypes for a loci with 3 alleles (shell colour in snails) and 4 alleles (coat colour in rabbits). At this point, the students are introduced to codominance and again they are challenged to apply their understanding to a new situation by working out the number of phenotypes in the inheritance of blood groups.
The rest of the lesson uses a step by step guide to complete a worked example to calculate an index of diversity. Students are challenged with a range of exam-style questions where they have to apply their knowledge and all mark schemes are displayed and clearly explained within the PowerPoint to allow students to assess their understanding and address any misconceptions if they arise.