Assertion (A): Electrical impulses are a faster means of communication in the body than chemical signals.
Reason (R): Chemical signals, unlike electrical impulses, can potentially reach all cells of the body regardless of nervous connections.
Generated by claude-sonnet-4-6 · 2026-06-26 01:00 · grounding rag
Model Answer
Option B — Both A and R are true, but R is NOT the correct explanation of A.
Electrical impulses are faster than chemical signals (A is true). Chemical signals (hormones) do reach all cells via blood regardless of nervous connections (R is true), but this wide reach explains the advantage of chemical signals, not why electrical impulses are faster.
Source: Chapter 6, Section 6.3 (Hormones in Animals)
Explanation
- A is true: The textbook states reflex arcs evolved because "the thinking process of the brain is not fast enough," implying electrical/nerve impulses are the faster mode.
- R is true: The textbook explicitly states that chemical signals "would reach all cells of the body" unlike electrical impulses via nerve cells whose range is limited.
- R does NOT explain A: R describes an advantage of chemical signals (wide reach), not the reason electrical impulses are faster. These are two separate facts about two different systems. Hence option B.