The size of the plant, its height affect the illumination of the leaves of different tiers of the plant (branches), although a leaf mosaic serves as a way out. Photosynthesis requires light (the main condition) and water with carbon dioxide. Different regions have different amounts of water. Plants of the second tier experience a greater lack of light than those in the first tier.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.