Why do plants need sunlight?

The life cycles of plants are the stages from seed to dispersal. In flowering plants the cycle goes like this: seeds in the soil germinate. They then grow roots and shoots. The next stage is a seedling which matures into an adult plant and makes flowers. Then the plant makes fruit which itself contains seeds. These are spread through dispersal and the cycle starts again. Did you know that some trees have lived for hundreds, or even thousands of years?