Final answer:
The statement is true; as more calcium ions enter the nerve terminal, more acetylcholine (ACh) is released, leading to muscle contraction.
Step-by-step explanation:
When an action potential travels down a motor neuron to the axon terminals, it triggers voltage-gated calcium channels to open. The influx of Ca2+ into the end bulb is crucial, as these ions facilitate the merging of synaptic vesicles with the presynaptic membrane, which leads to the release of neurotransmitters such as acetylcholine (ACh) into the synaptic cleft. As more Ca2+ ions enter, the amount of neurotransmitter released increases. This is because the presence of Ca2+ is directly related to neurotransmitter vesicle movement and the subsequent exocytosis of ACh, which then binds to ACh receptors at the motor end plate of a muscle fiber, leading to muscle contraction.