IB Biology HL C2.2 Neural Signalling Question Bank

Practise IB Biology HL C2.2 with membrane-potential traces and synapse data covering action potentials, neurotransmitters, saltatory conduction, summation and drugs.

Exam points

trace resting potential, threshold, depolarization and repolarization using sodium and potassium channel states
explain synaptic transmission, summation and saltatory conduction using calcium, vesicles, receptors and myelin
analyse oscilloscope or drug data to infer neural effects from pesticides, stimulants, cocaine or MDMA

Covered syllabus points

C2.2.1—Neurons C2.2.2—Resting potential generation C2.2.3—Nerve impulses as action potentials C2.2.4—Variation in impulse speed C2.2.5—Synapses as junctions C2.2.6—Neurotransmitter release C2.2.7—Excitatory postsynaptic potential C2.2.8 (HL)—Depolarization and repolarization C2.2.9 (HL)—Action potential propagation C2.2.10 (HL)—Oscilloscope traces C2.2.11 (HL)—Saltatory conduction C2.2.12 (HL)—Exogenous chemicals C2.2.13 (HL)—Inhibitory neurotransmitters C2.2.14 (HL)—Summation C2.2.15 (HL)—Pain perception C2.2.16 (HL)—Consciousness

[Maximum number: 12]

(a)

Draw a labeled diagram to show the structure of a motor neuron.

[ 4 ]

(b)

Explain how nerve impulses pass from one neuron to another neuron.

[ 8 ]

[Maximum number: 4]

Outline how neurons generate a resting potential.

a. sodium-potassium pump

b. sodium $/ \mathrm{Na}^{+}$ out and potassium $/ \mathrm{K}^{+}$ in

OR

sodium $/ \mathrm{Na}^{+}$ concentration higher outside and potassium $/ \mathrm{K}^{+}$ higher inside

c. three $\mathrm{Na}^{+}$ pumped for every two $\mathrm{K}^{+}$ (hence negative inside)

OR

inside of axon holds negative ions/ $\mathrm{Cl}^{-}$ ions/negatively charged proteins/organic anions (hence negative inside)

d. by active transport / using ATP

e. inside (of axon/neuron) is negative in comparison to outside

OR

electrochemical concentration/charge difference (across the membrane) is the resting potential

f. resting potential is -70 mV

4 max

[Maximum number: 1]

Neurons transmit electrical impulses. Which statement describes part of this process?

$\mathrm{K}^{+}$ ions are pumped out of the cell to depolarize the membrane.

Ion channels let $\mathrm{K}^{+}$ diffuse into the cell to depolarize the membrane.

$\mathrm{Na}^{+}$ ions are pumped into the cell to repolarize the membrane.

Ion channels let $\mathrm{Na}^{+}$ diffuse into the cell to depolarize the membrane.

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Covered syllabus points

C2.2 Neural signalling question 1

Question (a)

Question (b)

C2.2 Neural signalling question 2

C2.2 Neural signalling question 3