The fundamental excitable cell in the nervous system is the see concept 49.1 (page 1084)

Neuron 

Neuron can be defined as excitable cell that usually carries, processes and transmit impulses or electrical signals. Thus, they are known to be basic unit of the nervous system which includes the spinal cord and brain. However, the signals between s neurons occur via certain connections called synapses.

the calvin cycle has three stages. in stage 1, the enzyme rubisco incorporates carbon dioxide into an organic molecule. in stage 2, the organic molecule is reduced. in stage 3, rubp, the molecule that starts the cycle, is regenerated so that the cycle can continue

the statement is true