Practice IB Biology Topic C2.2 Neural Signalling with authentic exam-style questions for both SL and HL students. This question bank focuses on the exact syllabus content for C2.2 Neural Signalling and mirrors Paper 1A, 1B, 2 style where relevant.
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Which statement best explains why the inside of a resting neuron is negative relative to the outside?
Cell Q contracts after depolarization. Which junction type and transmission direction are supported?
| Cell stimulated | Neurotransmitter detected in cleft | Response in other cell |
|---|---|---|
| P | yes | Q depolarizes |
| Q | no | P unchanged |
With P and Q active, synapse S is blocked. Which change at T follows from the circuit and trace?
In a pain reflex arc, what type of neuron connects the sensory and motor neurons in the spinal cord?
Assume simultaneous changes add. Which input combination reaches threshold?
| Quantity | Membrane-potential change / mV |
|---|---|
| Resting potential | −70 |
| Threshold potential | −55 |
| One excitatory input | +6 |
| One inhibitory input | −4 |
Sodium ions diffuse in faster than potassium ions diffuse out.
Potassium ions diffuse out faster than sodium ions diffuse in.
Calcium ions diffuse in faster than potassium ions diffuse out.
Chloride ions diffuse in faster than potassium ions diffuse out.
Neuron–neuron synapse; transmission from Q to P
Neuron–effector synapse; transmission from Q to P
Neuron–neuron synapse; transmission from P to Q
Neuron–effector synapse; transmission from P to Q
