Ib Biology Nerve Impulses

What is the normal resting potential of a neuron cell membrane?

• +40mV
• -30mV
• +55mV
• -70mV

Which ions are involved in an action potential?

• Na; Cl
• Na; K
• K; Cl
• Na; Ca

The sodium potassium pump restores the resting potential. By which process does this work? 

• Osmosis
• Diffusion
• Facilitated diffusion
• Active transport

A membrane potential becoming less negative is called

• hyperpolarization
• depolarization
• repolarization
• polarization

In resting potential, neurons have more _________ on the outside of the cell membrane.

• K+
• NaCl
• Na+
• Cl-

What number(s) on the graph represents the THRESHOLD level of stimulus?

• 1 and 5

• 2

• 3

• 6

When a membrane potential reaches +30mV, ________ channels open, ________ occurs, and ________ channels close.

• Sodium, depolarization, potassium
• Potassium, depoloarization, sodium
• sodium, repolarization, potassium
• postassium, repolarization, sodium

The sodium-potassium pump....

• Sends (Na⁺) into the cell
• Sends (K⁺) into the cell
• Exchanges (K⁺) & (Na⁺) during depolarization
• Exchanges (K⁺) & (Na⁺) during hyperpolarization

At what stage are both ions present in large concentrations INSIDE the neuron?

• Depolarizarion
• Repolarization
• Hyperpolarization
• Resting Potential

When is the potassium channel open?

• during rest only

• during repolarization only

• during depolarization only

• all the time