As the members of a given generation age, their instinct of social conservation becomes stronger, which inevitably and necessarily brings them into conflict with the normal attribute of youthâinnovation. Other important theorists of the 19th century were John Stuart Mill and Wilhelm Dilthey.
Plants require more than just water and sunlight to grow. They also require many nutrients found in the soil. One of the most important nutrients required for plant growth is nitrogen. Nitrogen is used to build plant proteins and nucleic acids, including DNA.
In the leaves of a plant is a substance called chlorophyll. Chlorophyll makes leaves green. It also traps the energy from the sun so the plant can use it. When plants take carbon dioxide from the air, they release oxygen. Animals use this oxygen to grow. We release carbon dioxide, which the plants use. Plants also need minerals from the soil to grow. Nitrogen helps them grow and make leaves. Phosphorus helps grow strong roots. Potassium helps the plant make fruit and it keeps them healthy. Plants need large amounts of nitrogen, phosphorus and potassium. The soil doesnât always have enough of these nutrients. Gardeners use fertilizer to give plants more nutrients. Fertilizers are sort of like vitamins for plants.