Edexcel GCSE Biology, topic 3
Genetics
Genetics explains how characteristics are passed from parents to offspring. This topic covers reproduction and meiosis, the structure of DNA, how genes code for proteins, patterns of inheritance, and the causes of variation.
Examined in Paper 1 (1 hour 45 minutes, 100 marks).
Revision notes
Worksheet
FlashcardsSubtopics
Work through them in order. Each one has notes, exam questions and flashcards, and a PDF of each.
- 1Reproduction and meiosis Spec 3.1B–3.3Compare asexual and sexual reproduction, and explain how meiosis makes genetically different gametes.NotesQuestions 5Flashcards 8
- 2DNA and the genome Spec 3.4–3.6Describe the structure of DNA, define the genome and a gene, and explain how DNA is extracted from fruit.NotesQuestions 5Flashcards 10
- 3Protein synthesis and gene variants Triple onlyHigher tierSpec 3.7B–3.10BExplain how the order of bases decides protein shape, describe transcription and translation, and how gene variants change phenotype.NotesQuestions 5Flashcards 10
- 4Inheritance Spec 3.11B–3.18BMendel's work, alleles and key terms, monohybrid crosses, pedigrees, sex determination, ABO blood groups and sex-linked disorders.NotesQuestions 8Flashcards 20
- 5Variation, mutations and the Human Genome Project Spec 3.19–3.23Causes of variation, mutations and their effects, characteristics controlled by many genes, and the Human Genome Project.NotesQuestions 5Flashcards 9
Whole topic
When you have done the subtopics: test yourself on everything, or print the lot.