These wavelengths can be used to identify the substance. Nervous systems are formed from specialized cells that conduct signals rapidly through the long cell extensions that make up nerves. The nerve cells communicate with each other by secreting specific excitatory and inhibitory molecules. In sense organs, specialized cells detect light, sound, and specific chemicals and enable animals to monitor what is going on in the world around them. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change.
Plants also respond to stimuli.
Students should be able to identify new problems or needs and to change and improve current technological designs. Students should demonstrate thoughtful planning for a piece of technology or technique. Students should be introduced to the roles of models and simulations in these processes. A variety of skills can be needed in proposing a solution depending on the type of technology that is involved. Solutions can also be implemented using computer software.