Receptor sites for neurotransmitters are present on

Options

A. membranes of synaptic vesicles
B. pre-synaptic membrane
C. tips of axons
D. post-synaptic membrane

Explanation

**Step-by-Step Solution:**

1. **Understanding Neurotransmitters**: Neurotransmitters are chemical messengers secreted by neurons (nerve cells) that transmit signals across synapses to communicate with other neurons.

2. **Structure of Neurons**: A typical neuron consists of dendrites, a cell body, an axon, and axon terminals (synaptic knobs). The dendrites receive signals, while the axon transmits them.

3. **Synaptic Transmission**: When a nerve impulse reaches the axon terminal, neurotransmitters stored in vesicles are released into the synaptic cleft, which is the gap between two neurons.

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