🧬 Cells and DNA

Your whole body is built from tiny living building blocks called cells, far too small to see without a microscope. You have trillions of them, and different kinds do different jobs: muscle cells pull, blood cells carry oxygen, and brain cells send messages. Together they make all of you.

Inside almost every cell is a set of instructions called DNA, a bit like a recipe book for building and running your body. It decides things like the colour of your eyes and how tall you might grow. Your DNA is a mix from your parents, which is why you share features with your family.

You look like your family because you inherited a mix of their DNA, half from each parent. That mix decides features like your hair, eye colour and the shape of your face. Since the blend is different for everyone, even brothers and sisters do not look exactly alike.

Your body grows and repairs itself because cells can copy themselves. One cell splits neatly into two, each with the same instructions, then those split again. This is how a small scrape heals over and how you grew from a single tiny cell into the whole of you.