Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain why a change in allele frequencies across generations is evidence that a population has evolved. (Guide: “What ‘evolution’ means in a population”)
- I can explain why mutation is random, why it is the source of new alleles, and why on its own it changes frequencies slowly. (Guide: “Mutation”; Practice Q7)
- I can explain genetic drift as chance sampling, and why it is stronger in small populations. (Guide: Figure 1; Practice Q1, Q4)
- I can distinguish the bottleneck effect from the founder effect and give an example of each. (Guide: Figure 2, “The founder effect”; Practice Q5, Q6)
- I can explain how gene flow adds or removes alleles and why it stops connected populations diverging into separate species. (Guide: “Gene flow”; Practice Q3)
Calculation and skills
- I can calculate allele frequencies from genotype counts, doubling homozygotes, and check that they add to 1. (Guide: Worked example 1; Practice Q2, Q5)
- I can calculate the new allele frequency when migrants join a population. (Guide: Worked example 2)
- I can describe replicate results using ranges and counts of fixed or lost alleles. (Practice Q4)
- I can calculate percentage changes in hatching success or allele numbers from a table. (Practice Q6)
Reasoning
- I can state a null hypothesis and predict results for an investigation of drift or selection. (Guide: Worked example 1; Practice Q4, Q5)
- I can explain how a bottleneck lowers variation and can make harmful recessive alleles more common, and how gene flow can rescue a population. (Practice Q6)
- I can explain how drift lets a small population diverge from others of the same species. (Guide: “Genetic drift”; Practice Q3)
All ticked? Move on to Topic 7.5, Hardy–Weinberg Equilibrium, or return to the course roadmap.