Go cotton Wool

Well the bean is still growing! It now stands well above the top of the cup in which is was planted. However; the leaves seem to now be getting a few black spots on them which have not been noticeable previously. On research I have found out that plants obtain essential minerals from the soil. The most important nutrients are Nitrogen, phosphorus and potassium. Although these are not needed to produce food as plants produce food through photosynthesis, plants need these nutrients and minerals in order to maintain cell walls, cell membranes, proteins and plant DNA. Magnesium, iron and sulphur are used in the manufacture of chlorophyll and are also important. If these minerals are usually found in soil it would be a safe assumption that my bean is not getting these minerals from the cotton wool. As I mentioned in my last post the bean had enough energy within it to successfully germinate. However; now it is becoming a plant, perhaps the black spots on the leaves indicate a deficiency. If the plant is not getting enough minerals to make chlorophyll then this maybe a reason why some parts of the leaves are black not green. I will keep a close eye on it and comment further at a later date!