Edexcel GCSE Combined Science, topic 3
Genetics
Genetics explains how characteristics are passed from parents to offspring. This topic covers meiosis, the structure of DNA and the genome, patterns of inheritance, and the causes of variation.
Revision notes
Worksheet
FlashcardsSubtopics
Work through them in order. Each one has notes, exam questions and flashcards, and a PDF of each. Triple-only subtopics are left out.
- 1Reproduction and meiosis Spec 3.1B–3.3How meiosis makes four genetically different gametes with half the number of chromosomes, and how fertilisation restores the full number.NotesQuestions 1Flashcards 4
- 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
- 3Inheritance Spec 3.11B–3.18BAlleles and key genetic terms, monohybrid crosses and family pedigrees, sex determination, and calculating and analysing the outcomes of crosses.NotesQuestions 5Flashcards 13
- 4Variation, 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
Not in Combined Science: Protein synthesis and gene variants.
Whole topic
When you have done the subtopics: test yourself on everything, or print the lot.