Answer:
Weather conditions
Explanation:
Food can be limited based on location, however, scientists can control what kind of food it is. Soil can be tested and experimented on. There can be a lot of it and different kinds. Space is fought over because of territories and is limited compared to how many people and animals there are. Weather is not something that can be controlled in an experiment since it is sporadic.
Triggering of the muscle action potential occurs after Ach binds to chemically gated channels in the motor end plate membrane. Acetylcholine (Ach) is a neurotransmitter produced by nerve cells.
An action potential is an electrical signal that travels along the cell membrane as a wave.
This action potential (muscle action potential) drives the contraction of muscle fibers.
When the action potential reaches the neuromuscular junction (i.e., the motor end-plate), acetylcholine (Ach) is released into the synaptic cleft.
Subsequently, Ach can bind and open specific channels localized on the surface of the muscle cells, thereby depolarizing them and triggering muscle contraction.
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Answer: the amount of caloric intake a food has
Explanation: