Transmission of messages within the nervous system
A - VCE - SSCE Biology - Question 6 - 2002 - Paper 1
Question 6
Transmission of messages within the nervous system
A. proceeds in both directions along a nerve axon.
B. involves both electrical impulses and chemical messengers.
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Worked Solution & Example Answer:Transmission of messages within the nervous system
A - VCE - SSCE Biology - Question 6 - 2002 - Paper 1
Step 1
A. proceeds in both directions along a nerve axon.
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Answer
This statement is incorrect. Transmission of messages typically proceeds unidirectionally along a nerve axon, from the axon terminal of one neuron to the dendrites of another.
Step 2
B. involves both electrical impulses and chemical messengers.
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Answer
This statement is correct. Messages in the nervous system use action potentials (electrical impulses) for long-distance signaling and neurotransmitters (chemical messengers) for communication across synapses.
Step 3
C. is slower via a myelinated axon than a non-myelinated axon.
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Answer
This statement is incorrect. Transmission is faster in myelinated axons due to the insulating properties of myelin, which allow the action potential to jump between nodes of Ranvier.
Step 4
D. relies on the active transport of a neurotransmitter across a synaptic gap.
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Answer
This statement is partially correct. Neurotransmitters diffuse across the synaptic gap, which is a passive process rather than active transport; however, active transport is involved in the reuptake of neurotransmitters after they have transduced the signal.
