Just click on the green flag! A taxis is the response of an organism to an environmental stimulus. Thigmotaxis is an organism’s response to contact with other organisms or objects in its environment. The paramecium’s method for navigating around an object in its environment is an example of thigmotaxis.
You may well think the simple movement strategy of moving forward until an object is struck, backing up a short distance, turning left or right through a small angle, and then moving forward again, is too simple to be of much use. But in nature, exactly this behavior can be found in simple organisms like the single-celled paramecium. This mode of motion is called kinesis kinesis (a movement that is a response to a stimulus but is not oriented with respect to the source of stimulation). Small hairs called cilia cover the outer body of a paramecium. These hairs act like tiny oars to propel the organism through water and also help the organism gather food. When a paramecium strikes an object in its environment, the cilia reverse direction moving the paramecium backwards. The organism then turns left or right through a small angle, and moves forward. By continually repeating this process the paramecium is able to move around obstacles in it path. In this simulation, the paramecium is swimming though a thin layer of water containing a grain of sand. The sprite 1 script models kinesis. Now, I need to model a euglena that propels itself with a single, long cilia and an amoeba that 'flows' pseudopods (false feet) to move. A detailed explanation of how the code is constructed can be had at www.scratch-blog.com
