A. Cells have characteristic structures and functions that make them distinctive.
B. Processes in a cell can be classified broadly as growth, maintenance, reproduction, and homeostasis.
C. Life can be organized in a functional and structural hierarchy ranging from cells to the biosphere.
D. Most multicellular organisms are composed of organ systems whose structures reflect their particular function.
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This tutorial explains that electrical signals cannot travel from one neuron to the next directly. The signal crosses the synapse in chemical form. One neuron releases chemicals in response to an action potential and the chemicals travel across the synapse and stimulate an action potential in the next neuron. These chemicals are called neurotransmitters.
Type: Tutorial