This engaging and fully-resourced lesson looks at the effects of stabilising, directional and disruptive selection as the three main types of selection. The PowerPoint and accompanying resources have been designed to cover the 3rd part of point 7.3 of the AQA A-level Biology specification which states that students should be able to identify each type of selection by its effect on different phenotypes.
The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This method is covered later in topic 7 so this section of the lesson is designed purely to generate changes in numbers of the organisms. Sketch graphs are then constructed to show the changes in the population size in this example. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.
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AQA A-level Biology Topic 7: Genetics, populations, evolution and ecosystems
This bundle contains 15 fully-resourced and detailed lessons that have been designed to cover the content of topic 7 of the AQA A-level Biology specification which concerns genetics, populations, evolution and ecosystems. The wide range of activities included in each lesson will engage the students whilst the detailed content is covered and the understanding and previous knowledge checks allow them to assess their progress on the current topic as well as challenging them to make links to other related topics. Most of the tasks are differentiated to allow differing abilities to access the work and be challenged. The following sub-topics are covered in this bundle of lessons: * The use of genetic terminology * The inheritance of one or two genes in monohybrid and dihybrid crosses * Codominant and multiple alleles * The inheritance of sex-linked characteristics * Autosomal linkage * Epistasis as a gene interaction * The use of the chi-squared test * Calculating allele frequencies using the Hardy-Weinberg principle * Causes of phenotypic variation * Stabilising, directional and disruptive selection * Genetic drift * Allopatric and sympatric speciation * Species, populations, communities and ecosystems * Factors affecting the populations in ecosystems * Estimating the size of a population using randomly placed quadrats, transects and the mark-release-recapture method * Conservation of habitats frequently involves the management of succession This is one of the 8 topics which have to be covered over the length of the 2 year course and therefore it is expected that the teaching time for this bundle will be in excess of 2 months If you want to see the quality of the lessons before purchasing then the lessons on codominant and multiple alleles, epistasis and phenotypic variation are free resources to download
£20.00
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Topic 7.3: Evolution may lead to speciation (AQA A-level Biology)
Each of the 4 lessons included in this bundle are fully-resourced and have been designed to cover the content as detailed in topic 7.3 (Evolution may lead to speciation) of the AQA A-Level Biology specification. The specification points that are covered within these lessons include: * Phenotypic variation within a species * The effects of stabilising, directional and disruptive selection * The importance of genetic drift in causing changes in allele frequency * Allopatric and sympatric speciation The lessons have been written to include a wide range of activities and numerous understanding and prior knowledge checks so students can assess their progress against the current topic as well as be challenged to make links to other topics within this module and earlier modules If you would like to see the quality of the lessons, download the phenotypic variation lesson which is free
£6.50
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A good resource, detailed and fun way to teach the topic. However 7.3 #2 is not in the bundle and#3 refers to the presentation.
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