Guide: GRADED A+. Questions
and Verified Answers. Latest
2026 Update
1. Which structure can be found exclusively at an electrical synapse?
a. Synaptic cleft
b. Synaptic vesicle
c. Connexon
d. Neurotransmitter receptor
e. Presynaptic membrane - Ans✔✔-c. Connexon
2. Presynaptic and postsynaptic neurons that form _______ synapses are
connected via _______.
a. chemical; connexons
b. chemical; neurotransmitter release
c. electrical; gap junctions
d. electrical; the synaptic cleft
e. electrical; synaptic vesicles - Ans✔✔-c. electrical; gap junctions
3. How many connexin subunits form one complete synaptic channel?
,a. 4
b. 6
c. 10
d. 12
e. 16 - Ans✔✔-d. 12
4. Which substances diffuse through connexon channels between pre- and
postsynaptic neurons?
a. Ions
b. Second messengers
c. Small proteins
d. ATP
e. All of the above - Ans✔✔-e. All of the above
5. Which feature of an electrical synapse allows synchronizing the electrical
activity of multiple neurons?
a. Fast speed of transmission
b. Ability of neurons to form gap junctions with glial cells
c. Bidirectional transmission of electrical signals
d. Slow transmission of signals
e. Bidirectional transmission of chemical signals - Ans✔✔-c. Bidirectional
transmission of electrical signals
6. What is the action of the neurotransmitter at a chemical synapse?
a. It acts on receptors in the postsynaptic membrane.
b. It electrically activates the presynaptic neuron.
, c. It crosses the postsynaptic membrane and then activates ion channels in the
postsynaptic neuron.
d. It depolarizes the postsynaptic membrane by delivering an electrical charge.
e. It transfers an action potential from the presynaptic neuron to the
postsynaptic neuron. - Ans✔✔-a. It acts on receptors in the postsynaptic
membrane.
7. Which event is the first in the series of events that take place during
chemical synaptic transmission?
a. Neurotransmitter binds to its receptors.
b. Influx of Ca2+ in the presynaptic terminal.
c. Voltage-gated Ca2+ channels open.
d. Neurotransmitter is released into the synaptic cleft.
e. Synaptic vesicles fuse with the presynaptic membrane - Ans✔✔-c. Voltage-
gated Ca2+ channels open.
8. At which point during signal transmission at a chemical synapse is exocytosis
occurring?
a. As neurotransmitter binds to its receptors
b. While Ca2+ enters the presynaptic terminal
c. As voltage-gated Ca2+ channels are opening
d. During neurotransmitter release into the synaptic cleft
e. During reuptake, as synaptic vesicles are reformed from the plasma
membrane - Ans✔✔-d. During neurotransmitter release into the synaptic cleft
The figure shows an electron micrograph of a chemical synapse in the cerebral
cortex. Which statement about this synapse is accurate?