Cells · DNA · Evolution · Ecosystems
Life, broken down.
Ten plain-English lessons across the breadth of biology. 150+ practice questions with explanations. Interactive Punnett-square calculator, Hardy-Weinberg equilibrium solver, and DNA codon translator. Free, forever, for anyone curious about how living things actually work.
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Quick Start
Where to begin.
Core Topics
Ten lessons cover the whole field.
History
Case studies.
Thinkers
Famous biologists.
Timeline
Key milestones in biology.
Numbers
Life by the numbers.
Deep Dives
Concepts worth understanding.
FAQ
Common questions, plain answers.
Comparison
Kingdoms of life, side by side.
Reference
Mass extinctions through history.
Reference
Levels of biological organization.
Debates
Open questions in biology.
Formulas
Core biology formulas.
Step by Step
Lessons that teach.
Ten core biology topics, each with worked examples and three quick practice questions. About 10 to 15 minutes per lesson. Tap any to start.
Targeted Practice
Drill the concepts.
Quick 10-question quizzes from the full question bank. Each question is explained whether you get it right or wrong.
Interactive Tools
Numbers you can play with.
Plug in real values. Punnett squares, Hardy-Weinberg, codon translation, population growth, carbon dating.