A doffer is someone who removes bobbins, pirns or spindles holding spun fiber such as cotton or wool from a spinning frame and replaces them with empty ones. Historically, spinners, doffers, and sweepers each had separate tasks that were required in the manufacture of spun textiles. From the early days of the industrial revolution, this work, which requires speed and dexterity rather than strength, was often done by children. After World War I, the practice of employing children declined, ending
For a plant organ to bend in response to a stimulus, differential growth of cells on either side of the organ is required. For example, for the stem of a plant to bend toward a light source, cells on the shaded side of the stem near the shoot tip must elongate faster than cells on the lighted side.
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.