Why do seeds sprout?
The short answer
When a seed absorbs water, its stored chemical processes restart and use stored food to grow a root and shoot.
How it works
Germination usually needs water, oxygen, and a suitable temperature. The first root takes up water and minerals, while the shoot grows toward light. Stored food fuels the seed until leaves can photosynthesize.
A familiar example
A bean on moist cotton can show the early stages of germination even without soil.