Question

Which states that describe the synaptic vesicle are correct? a. In a neuron synaptic vesicles are also called neurotransmitter vesicles b. Vesicles store neurotransmitters and are released only during potassium- regulated exocytosis. c. Vesicles are not required for propagation of nerve impulses. d. ALL of the above

Short answer

Answer: In a neuron, synaptic vesicles are also called neurotransmitter vesicles.

Step-by-step solution

Statement a

Let's analyze statement a: "In a neuron synaptic vesicles are also called neurotransmitter vesicles." This statement is true. Synaptic vesicles, which are small membrane-bound structures, store neurotransmitters in neurons. Hence, they are also referred to as neurotransmitter vesicles.

Statement b

Let's analyze statement b: "Vesicles store neurotransmitters and are released only during potassium-regulated exocytosis." This statement is partially correct. While it's true that vesicles store neurotransmitters and are responsible for their release during exocytosis, the process that triggers exocytosis is not exclusively regulated by potassium. The release of neurotransmitters into the synapse is triggered by an influx of calcium ions in response to an action potential.

Statement c

Let's analyze statement c: "Vesicles are not required for propagation of nerve impulses." This statement is false. Synaptic vesicles play a crucial role in transmitting nerve impulses across synapses by releasing neurotransmitters, enabling the signal to travel from one neuron to the other. The absence of synaptic vesicles would disrupt nerve impulse transmission and thus are required for propagation of nerve impulses.

Statement d

Let's analyze statement d: "ALL of the above." Since statement c is false and statement b is partially correct, statement d is also false. Based on this analysis, the only correct statement that describes the synaptic vesicle is statement a: "In a neuron synaptic vesicles are also called neurotransmitter vesicles."