Select the incorrect statement regarding synapses :
Answer: (D) Impulse transmission across a chemical synapse is always faster than that across an electrical synapse. Answer: (d) — The claim that chemical synaptic transmission is always faster than electrical transmission is incorrect.
- A.The membranes of presynaptic and postsynaptic neurons are in close proximity in an electrical synapse.
- B.Electrical current can flow directly from one neuron into the other across the electrical synapse.
- C.Chemical synapse use neurotransmitters
- D.Impulse transmission across a chemical synapse is always faster than that across an electrical synapse✓
Correct Answer
(D) Impulse transmission across a chemical synapse is always faster than that across an electrical synapse
Solution & Explanation
Answer: (d) — The claim that chemical synaptic transmission is always faster than electrical transmission is incorrect. Solution: NCERT states that impulse transmission across an electrical synapse is always faster than that across a chemical synapse, because electrical current flows directly from one neuron to the next. Chemical synapses involve neurotransmitter release, diffusion and receptor binding, which introduces a delay. Therefore the statement that chemical transmission is faster than electrical is wrong — electrical synapses are faster. NCERT Reference: Ch 18, p.234, lines 13-14 — "Impulse transmission across an electrical synapse is always faster than that across a chemical synapse"