National Curriculum

KS3 Biology Topics

86 lessons across 16 units

This is the complete topic map for KS3 Biology— every part of the national curriculum for Key Stage 3, organised the way it's taught: 86 lessons across 16 units, from Body systems to Variation. Each topic below opens a focused revision lesson, so “what should we look at tonight?” always has an answer.

Body systems4 lessons

Human skeleton

Joints and movement

Muscles and antagonistic pairs

Cells10 lessons

Diffusion across membranes

Diffusion: particle picture

Preparing a microscope slide

Unicellular vs multicellular

Classification3 lessons

Classification keys

Species and classification

Climate and biodiversity2 lessons

Climate change and biodiversity

Digestive system5 lessons

Digestion and enzymes

Parts of the digestive system

Ecosystems14 lessons

Adaptations for survival

Conserving biodiversity

Food chains

Food webs

Pollination and food security

Pyramids of biomass

Pyramids of number

Evolution7 lessons

Natural selection

Gas exchange4 lessons

Breathing and gas exchange

Human gas exchange system

Measuring lung volume

Health and disease6 lessons

Lifestyle diseases

Inheritance4 lessons

Heredity introduction

Nutrition6 lessons

Balanced diet

Energy in food: practical

Photosynthesis4 lessons

Adaptations of leaves: gas exchange

Adaptations of leaves: light

Reproduction7 lessons

Gametes and fertilisation

Gestation and birth

Maternal lifestyle and the foetus

Reproduction and inheritance

Reproductive organs

Reproduction in plants4 lessons

Flower structure

Pollination and fertilisation

Respiration4 lessons

Aerobic respiration

Anaerobic respiration in humans

Anaerobic respiration in microorganisms

Cellular respiration

Variation2 lessons

Continuous vs discontinuous

Variation within a species

What KS3 Biology covers

The course is organised into 16 units: Body systems (4 lessons), Cells (10 lessons), Classification (3 lessons), Climate and biodiversity (2 lessons), Digestive system (5 lessons), Ecosystems (14 lessons), Evolution (7 lessons), Gas exchange (4 lessons), Health and disease (6 lessons), Inheritance (4 lessons), Nutrition (6 lessons), Photosynthesis (4 lessons), Reproduction (7 lessons), Reproduction in plants (4 lessons), Respiration (4 lessons) and Variation (2 lessons). Together that's 86 lessons — the whole course, with nothing skipped and nothing added.

How to revise with this page

Little and often beats cramming. One topic a night, done properly — read it, try the questions, check yourself — moves a grade more than a weekend binge the week before the exam. The list above is deliberately complete so you can tick through it a topic at a time.

Start from what's coming up, not from the beginning. If a class test or mock is near, open the unit it covers and work through those topics first. Between assessments, work through units in order — later topics usually build on earlier ones.

For parents:you don't need to know the subject to help. Ask which topic tonight's lesson was, open it here, and let them teach it back to you — explaining something out loud is one of the most effective revision techniques there is. At KS3 the habit matters more than the coverage: little routines now are what GCSE revision gets built on.

Common questions

What topics are in KS3 Biology?

KS3 Biology covers 86 topics across 16 units: Body systems, Cells, Classification, Climate and biodiversity, Digestive system, Ecosystems, Evolution, Gas exchange, Health and disease, Inheritance, Nutrition, Photosynthesis, Reproduction, Reproduction in plants, Respiration and Variation. Each topic on this page opens a focused revision lesson.

How many topics are in KS3 Biology?

There are 86 topics in KS3 Biology, grouped into 16 units.

Is KS3 Biology the same for every exam board?

KS3 Biology follows the national curriculum, so it isn't tied to a specific exam board — boards like AQA and Edexcel set GCSE specifications (Key Stage 4), not KS3. This page lists the national-curriculum topics for KS3 Biology.