Describe structure of chemical synapse

one neuron release neurotransmitter molecules into small space ( the synaptic clef ) that is adjacent to another neutron. The neuron transmitters are contained within small sacs called synaptic vesicles, and released into the synaptic clef by exocytosis

Explanation:

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

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