Q1. [1] straightforward exam-ready
When a nerve impulse reaches the end of an axon, what event allows it to continue to the next neuron?
- A The electrical impulse jumps directly across the gap.
- B Chemicals are released that cross the synapse and start an impulse in the next dendrite.
- C The axon elongates to physically touch the next neuron.
- D The cell body of the next neuron is stimulated directly by the blood.
Generated by claude-sonnet-4-6 · 2026-06-26 01:00 · grounding rag
Model Answer
Answer: B
When a nerve impulse reaches the end of an axon, chemicals are released that cross the synapse (gap) and start a similar electrical impulse in the dendrite of the next neuron.
Source: Chapter 6, Section 6.1 – Animals – Nervous System
---
Explanation
- The passage clearly states: "At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap, or synapse, and start a similar electrical impulse in a dendrite of the next neuron."
- Option A is wrong — electrical impulses do not jump across the gap directly; chemical transmission bridges the synapse.
- Options C and D are completely incorrect and not supported by the text.
- Key term to remember: synapse = the gap between two neurons; transmission across it is chemical, not electrical.