Video narration
How can a hard, dry bean become a whole plant in your cup? The bean takes in water, swells, and splits its outer coat. This start is called germination: the seed begins to grow. It also needs air and suitable warmth, but not sunlight yet. It happens bit by bit. Here's the surprise: its first food doesn't come from the soil. The bean carries a small food supply inside. That food powers its first steps. A root emerges first and grows down, taking in water. Then a shoot rises through the soil, reaching toward the light. Both use food stored inside the seed. When leaves open, everything changes. They catch light and begin making food for the young plant. So the bean in your cup becomes a plant by using stored food to grow roots and shoots, then making its own food with new leaves.