I was just reading about the old classic experiment of growing cress in the dark vs. the light. Cress grown in the dark grows much taller (in an attempt to reach light I presume) and also has much paler, yellow leaves.
Why are these leaves yellow? Are there not enough resources in the seed upon germination for it to synthesise sufficient chlorophyll? That means that the light allows the chlorophyll to be synthesised. Is it purely an energy thing?
Thanks as always.