AP Biology Midterm Review Ch 37+

In a simple synapse, neurotransmitter chemicals are released by

• cell bodies.

• axon hillocks.

• the dendritic membrane.

• the presynaptic membrane.

The operation of the sodium-potassium "pump" moves

• sodium and potassium ions into the cell.

• sodium and potassium ions out of the cell.

• sodium ions into the cell and potassium ions out of the cell.

• sodium ions out of the cell and potassium ions into the cell.

Action potentials in the heart move from one contractile cell to the next via

• myelinated motor neurons.

• chemical synapses using acetylcholine.

• electrical synapses using gap junctions.

• chemical synapses using norepinephrine.

ATP hydrolysis directly powers the movement of

• Ca++ into cells.

• Na+ into cells.

• Na+ out of cells.

• K+ out of cells.

Action potentials move along axons

• by activating the sodium-potassium "pump" at each point along the axonal membrane.

• more slowly in axons of large diameter as compared to those of small diameter.

• by the direct action of acetylcholine on the axonal membrane.

• more rapidly in myelinated than in nonmyelinated axons.

A toxin that binds specifically to voltage-gated sodium channels in axons would be expected to

• have most of its effects on the dendritic region of a neuron.

• increase the release of neurotransmitter molecules.

• prevent the depolarization phase of the action potential.

• prevent the hyperpolarization phase of the action potential.

Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?

• The postsynaptic cell produces an action potential.

• Ligand-gated channels open, allowing neurotransmitters to enter the synaptic cleft.

• Voltage-gated calcium channels in the membrane open.

• Synaptic vesicles fuse with the membrane.

In a simple synapse, neurotransmitter chemicals are received by

• axon hillocks.

• cell bodies.

• the dendritic membrane.

• the presynaptic membrane.

Neurotransmitters are released from axon terminals via

• diffusion.

• exocytosis.

• transcytosis.

• active transport.

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells?

• blood or tissue type of the patient

• lack of charge on the drug molecule

• hydrophobicity of the drug molecule

• similarity of the drug molecule to other molecules transported by the target cells