IB Biology SL C2.2.5 Synapses As Junctions Questions

Practise IB Biology SL 2.2.5 by tracing calcium entry, neurotransmitter release, diffusion and receptor binding across a synapse.

Syllabus
First assessment 2025
Course
Biology SL
Level
SL

Exam points

  • Explain one-way chemical synaptic transmission from presynaptic calcium entry and vesicle release to postsynaptic receptor activation.
  • Distinguish presynaptic and postsynaptic membrane locations and roles, including calcium channels, neurotransmitter release and receptors.
  • Explain why a narrow synaptic cleft increases the speed of neurotransmitter transmission.
  • Identify the synaptic junction region where chemical transmission occurs on a neuron diagram.

IB Biology SL C2.2.5 Synapses As Junctions Questions question 1

[Maximum number: 3]

The electron micrograph shows part of a synapse between two neurons.

Figure for Question IB Biology SL C2.2.5 Synapses As Junctions Questions question 1 — IB Biology SL

Question (a)

(a)

Distinguish between the presynaptic and postsynaptic membranes by giving two differences.

[ 2 ]

Question (b)

(b)

The gap between the presynaptic and postsynaptic membranes is very narrow. Suggest an advantage of this.

[ 1 ]
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