What you'll learn
How characteristics are inherited and species evolve.
Genetics
- DNA, genes and alleles; dominant and recessive.
- Meiosis produces gametes; Punnett squares and genetic crosses.
- Variation and mutation.
Evolution
- Natural selection (Darwin) and evidence from fossils.
- Examples such as antibiotic-resistant bacteria.
Exam tips
- Use a Punnett square to work out offspring ratios.
- Explain natural selection step by step (variation → survival → reproduction).
Common mistakes
- Confusing genotype and phenotype.
- Saying organisms 'choose' to adapt.