Final answer:
If acetylcholinesterase is poisoned or stopped, it would result in prolonged muscle excitation and contraction.
Step-by-step explanation:
When acetylcholinesterase is poisoned or stopped, it is unable to degrade acetylcholine (ACh) in the synaptic cleft. As a result, ACh cannot rebind to receptors and reopen its channel. This leads to prolonged muscle excitation and contraction, causing continuous and uncontrolled muscle activity.