paragraph: Leaves are the keys not only to plant life but to virtually all life on land. The primary role of leaves is to collect sunlight. This sunlight is needed for the plant to make food. Leaves vary in size, shape, and how they are arranged on stems. You can see examples of different types of leaves in Figure 3.4. Each type of leaf is well suited for the plants environment. It maximizes light exposure while conserving water. They also reduces wind resistance. Leaves also benefit the plant in some other way in its particular habitat. For example, some leaves are divided into many smaller leaflets. This reduces wind resistance and water loss. Leaves are basically factories for photosynthesis. A factory has specialized machines to produce a product. In a leaf, the 'machines' are the chloroplasts. A factory is connected to a transportation system that supplies it with raw materials and carries away the finished product. In a leaf, transport is carried out by veins containing vascular tissue. Veins carry water and minerals to the cells of leaves. They carry away dissolved sugar. 
question: A factory has specialized machines to produce a product and leaves basically have factories for what?
answer: Flowers