Learn biology by looking closer
A hands-on course that starts inside a single cell and works up to whole ecosystems: every lesson pairs readable theory with an interactive lab you can poke, feed, mutate and starve — then a short quiz locks it in. It ends with DNA you pull out of a strawberry with washing-up liquid.
The Cell
0/3Everything alive is made of cells, and every cell is a bag of water that controls what crosses its border and runs its chemistry with protein machines.
What Is Alive, and What a Cell Is
Biology's one universal claim: every living thing is made of cells, and every cell comes from another cell.
The Membrane & Getting Things Across
A cell is defined by its border. Two layers of fat decide what enters, what leaves, and what it costs.
Enzymes: Why Biology Happens at All
Most of life's reactions are far too slow at body temperature. Enzymes lower the hill — and their shape is the whole trick.
Energy
0/2Two reactions, run in opposite directions, power almost everything alive: one stores sunlight in sugar, the other spends it again.
Photosynthesis: Making Food from Light
Plants build sugar out of air and water using sunlight. Almost every calorie you have ever eaten started here.
Respiration: Spending the Sugar
Every cell runs the same reaction in reverse to get ATP — and how much it gets depends entirely on whether oxygen is available.
DNA & Proteins
0/4The molecule that stores the instructions, the machinery that copies it, and the code that turns four letters into every protein you are made of.
DNA: Four Letters, One Molecule
A ladder whose rungs can only pair one way — which is what makes it both an archive and a template.
Replication: Copying Three Billion Letters
Unzip the ladder, and each half specifies its own replacement. The proofreading is what makes it astonishing.
The Genetic Code: From Gene to Protein
Three bases name one amino acid. That lookup table is shared by every organism on Earth, and it is the closest thing biology has to a universal constant.
Mutations: When the Copy Is Wrong
One base in three billion. Sometimes it means nothing at all, sometimes it means sickle-cell anaemia — and the difference is mostly about reading frames.
The Kitchen Capstone
0/1Three units of theory, cashed in: pull real DNA out of a strawberry with washing-up liquid, salt and cold spirit, and lift it out on a stick.
Progress & backup
this browser onlyProgress lives in this browser; sync keeps a server copy reachable only by your code, and exports are plain files you own. Imports and links always merge — nothing is overwritten.