Plants: what each part does and what a plant needs

Making its own food

A plant is not fed the way an animal is. It makes its own food in the leaves, using light, water and a gas from the air. That is why light is not optional for a plant — without light there is no food, and the plant turns pale and dies.

Water travels up

Roots take in water; the stem carries it up to every leaf and flower. Put a white flower in coloured water and after a day the petals are streaked with the colour, which proves water really did travel up the stem.

Soil is not food

Soil holds water and a few minerals, and it holds the roots in place. It is not the plant's food.