All AP Biology Resources
Example Questions
Example Question #41 : Understanding Neural Cells
What are diseases associated with demyelination?
Anemia
Neurodegenerative diseases
HIV
Epilepsy
Neurodegenerative diseases
Demyelination of axons is associated with neurodegenerative diseases. The loss of myelination negatively impacts the ability of neurons to transmit signals throughout the body. Examples of demyelination diseases are multiple sclerosis and Guillain–Barre syndrome. HIV is a viral infection that attacks the immune system. Anemia is a blood disorder in which there are not enough functioning red blood cells to provide the body tissues with sufficient oxygen. Epilepsy is a disease that involves frequent seizures.
Example Question #42 : Understanding Neural Cells
What is true about saltatory conduction?
It is the method of action potential transmission in myelinated axons
The signal is passed from one node of Ranvier to another
It increases the rate of signal transmission
All of these
All of these
Saltatory conduction is a type of signal transmission in myelinated axons. Here, the action potential (wave of sodium ions) passes from one node of Ranvier to another, which increases the rate of transmission.
Example Question #43 : Understanding Neural Cells
What statement best defines the membrane potential?
It is the electrical charge reached by action potential
Difference in electrical charge between the interior and exterior of the cell
The membrane potential in a cell never changes
The difference in electrical charge across a membrane is determined only by sodium ion concentration
Difference in electrical charge between the interior and exterior of the cell
Membrane potential is a term used to describe the difference in electrical charge across a cell membrane. This difference is determined by ion concentration inside and outside of the cell and can change due to ion-gated channels and ion pumps, among others. Membrane potential allows cells to transmit electrical signals. During an action potential, the membrane is said to be depolarized, which means the membrane potential becomes less negative.
Example Question #44 : Understanding Neural Cells
What is the resting potential of a cell?
The static membrane potential of a cell
Rapid rise and fall of membrane potential
The maximum difference in electrical charge across a membrane
The static membrane potential of a cell
The resting potential of a cell is the relatively static membrane potential that serves as the baseline voltage of a cell, which is about in neurons. The resting potential stands in opposition to the action potential.
Example Question #45 : Understanding Neural Cells
What does the threshold potential precede?
Voltage
Membrane potential
Action potential
Resting potential
Action potential
The threshold potential of a cell is a specific membrane potential that is needed in order to initiate action potential. Therefore, threshold potential precedes action potential. Note that reaching the threshold potential triggers a positive feedback loop, causing more sodium to rush into the cell, further depolarizing the membrane potential.
Example Question #46 : Understanding Neural Cells
The axon hillock connects what two areas of a neuron?
Soma and dendrite
Dendrite and synapse
Axon and soma
Axon and dendrite
Axon and soma
The axon hillock is the area of a neuron that connects the soma and axon. This is also the area of the of the neuron that "decides" whether an action potential would be initiated or not, depending on whether the cell has reached threshold or not.
Example Question #121 : Types Of Cells And Tissues
What does not occur in the presynaptic terminal?
Recycling of unused neurotransmitters
Calcium influx
Exocytosis of neurotransmitters
Binding of neurotransmitters to receptors
Binding of neurotransmitters to receptors
In the presynaptic terminal, the action potential causes an influx of calcium. Rising calcium levels stimulates exocytosis of neurotransmitters, which bind to post-synaptic receptors. Unused neurotransmitters are recycled by the pre-synaptic cell or degraded in the synaptic cleft.
Example Question #122 : Types Of Cells And Tissues
How is an electrical signal transmitted from a presynaptic terminal to a postsynaptic terminal?
Neither endocytosis of neurotransmitters by the postsynaptic terminal nor binding of neurotransmitters to receptors on the postsynaptic terminal
Endocytosis of neurotransmitters by the postsynaptic terminal
Both endocytosis of neurotransmitters by the postsynaptic terminal and binding of neurotransmitters to receptors on the postsynaptic terminal
Binding of neurotransmitters to receptors on the postsynaptic terminal
Binding of neurotransmitters to receptors on the postsynaptic terminal
Signal transmission from presynaptic terminal to postsynaptic terminal occurs when neurotransmitters bind to receptors on the postsynaptic terminal. Once the neurotransmitter binds to the receptors on the postsynaptic neuron's cell membrane, the postsynaptic cell can be induced (excited) to fire another action potential, or inhibited based on the type of neurotransmitter and/or receptor that is bound.