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.
Detection of Stimuli. In order for an organism (such as a plant or an animal) to adjust to a change in the environment, it must first be able to detect (or physically recognize) the change. This detection of a stimulus is called sensitivity.timuli and responses are not only associated with the external environment, but are also found in the internal environment of organisms as well. Any stimulus within the body of the organism must be detected as well in order for the organism to survive.