increases genetic variation within a species Define genetic diversity 3.4.4 Genetic diversity and 11.3 6 Natural Selection Explain the advantages of adaptation genetic diversity Students can be provided with Describe the steps in the Genetic diversity as the number of scenarios which describe the theory of natural selection different alleles of genes in a variation within a population and a Explain the difference population. selection pressure. In pairs between directional and students could then predict what stabilising selection Genetic diversity is a factor they think will happen in future enabling natural selection to generations. A flow chart could be created to explain the steps The principles of natural selection involved in natural selection. There in the evolution of populations. are numerous YouTube clips to illustrate natural selection. Random mutation can result in • Direction and stabilising selection new alleles of a gene. can be illustrated in the form of a Many mutations are harmful • graph and described using but, in certain environments, the examples to visualise the selection. new allele of a gene might benefit its possessor, leading to increased reproductive success. The advantageous allele is • inherited by members of the next generation. As a result, over many • generations, the new allele increases in frequency in the population. Directional selection, exemplified by antibiotic resistance in bacteria, and stabilising selection, exemplified by birth weights. Natural selection results in species that are better adapted to their environment. These adaptations
increases genetic variation within a species 6 Natural Selection Students can be provided with scenarios which describe the variation within a population and a selection pressure. In pairs students could then predict what they think will happen in future generations. A flow chart could be created to explain the steps involved in natural selection. There are numerous YouTube clips to illustrate natural selection. Direction and stabilising selection can be illustrated in the form of a graph and described using examples to visualise the selection. Define genetic diversity Explain the advantages of genetic diversity Describe the steps in the theory of natural selection Explain the difference between directional and stabilising selection 3.4.4 Genetic diversity and adaptation Genetic diversity as the number of different alleles of genes in a population. Genetic diversity is a factor enabling natural selection to The principles of natural selection in the evolution of populations. • Random mutation can result in new alleles of a gene. • Many mutations are harmful but, in certain environments, the new allele of a gene might benefit its possessor, leading to increased reproductive success. • The advantageous allele is inherited by members of the next generation. • As a result, over many generations, the new allele increases in frequency in the population. Directional selection, exemplified by antibiotic resistance in bacteria, and stabilising selection, exemplified by birth weights. Natural selection results in species that are better adapted to their environment. These adaptations 11.3
Biology%20SoW%20Year%201.docx