WorksheetsBad Fish case study
Total questions: 14
Worksheet time: 7mins
What which of the following is considered the nerve impulse that is the main communicative signal in neurons?
a hypopolarizatioer
an action potential
a graded potential
an undershoot
all of the above
An action potential travels down what part of a neuron?
dendrites
cell body
axon
all of the above
none of the above
The movement of charged ions based on concentration gradients when the nerve is at rest….
Both Na+ and K+ will move OUT of the cell.
Both Na+ and K+ will move INTO the cell.
Na+ will move OUT and K+ will move INTO the cell.
Na+ will move IN and K+ will move OUT of the cell.
Neither Na+ nor K+ will move across the cell membrane via diffusion
When a neuron is stimulated, the area of the membrane at the point of stimulation becomes more permeable to Na+.
The membrane voltage will become < -70mV, because Na+ will move OUT of the cell
The membrane voltage will become >-70mV, because Na+ will move OUT of the cell.
The membrane voltage will become < -70mV because Na+ will move INTO the cell
The membrane voltage will become >-70mV because Na+ will move INTO the cell
At the peak of the action potential, Na+ voltage-gated channels close, and K+ voltage-gated channels open in response to positive membrane potential. To return the cell to its negative resting potential quickly:
.K+ will diffuse along its concentration gradient INTO the cell.
K+ will diffuse along its concentration gradient OUT of the cell.
Na+ will reverse its direction of diffusion OUT of the cell.
The sodium-potassium pump will move Na+ OUT of the cell and K+ INTO the cell
None of the above would return the cell to its negative resting potential quickly.
Dr. Westwood ate a meal of pufferfish and rice. As a result, he was a victim of pufferfish poisoning that caused his life-threatening symptoms of numbness, paralysis, irregular heartbeat, and difficulty breathing. Tetrodotoxin (TXX), found in pufferfish flesh, is a molecule that:
Blocks the release of neurotransmitters.
Kills T cells
Blocks voltage-gated sodium ion channels.
Blocks neurotoxins
Causes widespread blood clotting.
If tetrodotoxin (TXX) blocks voltage-gated sodium ion channels, which part of the action potential would be impacted?
A
B
C
D
more than one of these
Dr. Westwood experienced numbness after eating the pufferfish meal because TXX causes:
Motor neurons to fire continuously, overloading the brain with signals, resulting in numbness
Motor neurons to stop firing, preventing communication with the brain, resulting in numbness
Sensory neurons to stop firing preventing communication with the brain, resulting in numbness.
Sensory neurons to fire continuously, overloading the brain with signals, resulting in numbness.
None of the above explain why Dr. Westwood experienced numbness after his pufferfish meal.
Why did Dr. Westwood experience paralysis after eating the pufferfish meal?
TXX causes motor neurons to fire continuously, overloading the brain with signals, resulting in paralysis.
TXX causes motor neurons to stop firing, preventing communication with the muscles, resulting in paralysis.
TXX causes sensory neurons to stop firing preventing communication with the brain, resulting in paralysis.
TXX causes sensory neurons to fire continuously, overloading the brain with signals, resulting in paralysis
None of the above explain why Dr. Westwood experienced paralysis after his pufferfish meal.
What symptoms did Dr. Westwood experience after both his pufferfish meal and after handling the new bird species?
Nausea
Numbness
Paralysis
Difficulty breathing
More than one of the above
The toxin found in the bird feathers:
Affects neurotransmitterelease
Is found in birds that have eaten poison arrow frogs
Is the same toxin found in pufferfish flesh.
Affects voltage sensitive sodium channels.
Affects voltage sensitive potassium channels.
Choose the graph on the screen that most closely matches the graph you just created:
A
B
C
D
E
You experiment with higher concentrations of toxin and find cases when the cell could not repolarize at all or, if it began to repolarize, it immediately depolarized again. This tells you that the toxin:
Makes Na+ ion channels close too soon.
Prevents voltage-gated K+ channels from opening.
Increases the speed that Na+ ion channels open.
Prevents Na+ ion channels from closing.
Doesn’t affect the Na+ ion channels at all, it affects the sodium-potassium pump instead
In this case study, you have learned...
Poisons that affect nerves interfere with ion channels.
Never eat pufferfish
Science depends on accidental discoveries.
Electrical potentials across membranes can be manipulated with ion channels.
None of the above.
