Micro-WorldBiology1 min read

DNA

The instruction book that builds you — and most of every other living thing.

Zephyris (CC BY-SA 3.0)

Size: 2.00 nm

Picture this

If a single strand of DNA were as thick as a human hair, a flu virus alongside it would be the size of a small button in your palm.

By weight

A single cell's DNA weighs about six trillionths of a gram, yet codes for an entire person. All the DNA across your roughly thirty trillion cells together weighs less than half a kilo.

Fact

DNA is the instruction book your body uses to build you. Every cell carries the same complete copy — your eye colour, your height, the chance you'll inherit your father's allergies, all written into roughly two metres of DNA coiled inside that one cell. Reading those instructions is so reliable that a single hair, a stamp licked decades ago, or a cigarette butt left at a crime scene can identify exactly who it came from — which is why DNA has solved cases the police had given up on forty years earlier.

Glossary

Base pairHelixGenome

Did you know?

You and a chimpanzee share about 98.8% of your DNA. You and a banana share about 60%. And any two unrelated humans on the planet — strangers, neighbours, anyone — are 99.9% genetically identical. Everything you call 'different about people' is written in less than a tenth of one percent of your genome.

Quick facts

Identical twins share virtually all their DNA — but not their fingerprints, which form by chance in the womb.
Most Europeans and Asians carry roughly 1–2% Neanderthal DNA, inherited from interbreeding ~50,000 years ago.
Your body fixes thousands of DNA errors in each cell every day. Most cancers start when a single uncorrected error slips through.
Mitochondrial DNA passes only from mother to child — you can trace your direct maternal line back roughly 150,000 years to a single woman in Africa, nicknamed 'Mitochondrial Eve'.
Roughly two metres of DNA is coiled into nearly every cell in your body — packed so tightly the strand from one cell is shorter than a virus when folded.
The double helix was figured out in 1953. Rosalind Franklin's X-ray image (Photo 51) was central evidence — but she died before the 1962 Nobel Prize was awarded for the discovery.

Sources

Last updated 2026-05-17

Where this stop sits in each journey

You are here

Scale

DNA

The instruction book that builds you — and most of every other living thing.

Size

2.00 nm

Open stop

Tap a dot to preview it. Use the Open stop link to read its full page. Stops are arranged from smallest on the left to largest on the right.

Related stops

01Size100 pm

Atom

The smallest piece of any chemical element.

MatterMicro-World

02Size100 nm

Virus

Strands of code wrapped in protein.

BiologyPathogenMicro-World

03Size2.00 µm

Bacterium

Single-celled life, no nucleus required.

BiologyMicrobeMicro-World

Loading…

Quick facts

Identical twins share virtually all their DNA — but not their fingerprints, which form by chance in the womb.

Most Europeans and Asians carry roughly 1–2% Neanderthal DNA, inherited from interbreeding ~50,000 years ago.

Your body fixes thousands of DNA errors in each cell every day. Most cancers start when a single uncorrected error slips through.

Mitochondrial DNA passes only from mother to child — you can trace your direct maternal line back roughly 150,000 years to a single woman in Africa, nicknamed 'Mitochondrial Eve'.

Roughly two metres of DNA is coiled into nearly every cell in your body — packed so tightly the strand from one cell is shorter than a virus when folded.

The double helix was figured out in 1953. Rosalind Franklin's X-ray image (Photo 51) was central evidence — but she died before the 1962 Nobel Prize was awarded for the discovery.