A no-prep, 5-lesson science unit on KS3 Biology: inheritance, chromosomes, DNA and genes; a simple model of chromosomes, genes and DNA; the variation between individuals within a species being continuous or discontinuous; differences between species; heredity as the process by which genetic information is transmitted from one generation to the next, written for Key Stage 3, Years 7-9 (ages 11-14). Phenomenon-first and three-dimensional: every lesson opens with something to wonder about and builds toward the unit’s big question. Open and teach — full teacher plans, projectable slides, three differentiated pupil worksheets per lesson, a complete printable lab pack, a knowledge organiser, and a baseline + end-of-unit assessment.

Big question: How are instructions for life passed on, and why is every living thing a little bit different?

What’s included

• 5 × Teacher lesson plans (Word) on the 5E spine (Engage · Explore · Explain · Elaborate · Evaluate)
• 5 × Pupil worksheets in 3 differentiated tiers (Support / Core / Stretch)
• 5 × Projectable slide decks (PowerPoint, 16:9 widescreen)
• 1 × Full lab pack (Word) — investigation question, fair-test variables, household and lab equipment lists, a real risk assessment, a blank results table, and analysis + conclusion scaffolds
• 1 × Knowledge organiser (Word, A4 landscape)
• 1 × Baseline + end-of-unit assessment with a teacher answer key and three-dimensional items
• Hand-coded diagrams with clear labels for the unit’s key ideas — never AI-generated
• Original illustrations for every phenomenon hook

Lesson outline

1. Genes, chromosomes and DNA
2. How genes affect traits
3. Mutations: changes in genes
4. Sexual reproduction makes variation
5. Asexual reproduction makes clones