🧶 DNA, Chromatin & Cosmic Scale Investigations
In fact, 100% of all living organisms on planet Earth have DNA — humans, cats, trees, flowers, grass, and even microscopic bacteria! Just like human DNA decides your eye colour and height, plant DNA decides flower petal colour, how sweet an apple is, and how tall an oak tree can grow.
Why did the plant diagram say "Chromatin" instead of "DNA"? Because Chromatin IS DNA!
Chromatin KROH-muh-tin is the name for DNA neatly packaged around proteins.
If you stretch out the DNA inside just one single microscopic cell, it is 2 metres long! If you shoved 2 metres of loose thread into your pocket, it would tangle into an impossible knot. To keep it organized, the cell winds the DNA thread around tiny round protein spools called histones (HISS-tones).
The purple round protein spools.
One spool with DNA wrapped around it twice.
What it looks like under an electron microscope!
The X-shapes formed when chromatin supercoils!
All living things on Earth run on the exact same universal chemical programming language made of 4 letters: A, T, C, and G. A plant cell reads its DNA code to build plant proteins (like chlorophyll for catching sunlight), and an animal cell reads its DNA code to build animal proteins (like muscle and skin). The machinery and rules are identical!
Here is the step-by-step mathematical calculation comparing humans and the largest animal to ever live:
In Just ONE Cell
Taller than an adult human! Fitting 2 metres into a microscopic 0.006 mm nucleus is like packing 40 km of thread inside a single tennis ball!
In Your Whole Body
Your body has ~37 trillion cells. Tied end-to-end, your DNA could travel from Earth to the Sun and back over 300 times!
In a Blue Whale
A 150-tonne blue whale has up to 100 quadrillion cells. Stretched out, that is 200 trillion kilometres — long enough to reach Alpha Centauri and all the way back! 🚀