Hypothesize how this might represent something comparable to the way our nervous system functions. Concepts Nerve cells are called neurons. Neurons require a stimulus of a minimum strength to fire. The nerve impulse is propagated along the length of the nerve cell. After a neuron has fired, there is a refractory period during which it cannot fire.
Neurons use energy to reset their resting state so that they can fire again.
Preparation None, except for obtaining materials. If time is short, you can prepare the models ahead of time, or you can construct a single, larger model on a meterstick and use it for a demonstration of nerve impulse propagation. After the Exploration Expected Results When the first domino is toppled, it begins a chain reaction in which each subsequent domino is toppled until there are no more dominoes to topple. The dominoes cannot fall again until they are reset, which requires an input of human energy. In the same way, the nerve cell uses energy to redistribute ions and re-establish the resting state after a nerve impulse has propagated down the axon, and the nerve cannot fire again until this occurs.