State two limitations of electrical impulses in multicellular organisms. Why is chemical communication better than electrical impulses as a means of communication between cells in multicellular organisms?
Generated by claude-sonnet-4-6 · 2026-06-15 06:49 · grounding rag
Model Answer
Limitations of electrical impulses:
- Electrical impulses can only reach cells connected by nervous tissue; they cannot instruct all body tissues.
- The range of cells and tissues that can be reached is limited.
Why chemical communication is better:
Chemical signals (hormones) are released directly into the blood and carried to all cells of the body. This allows wide-ranging, coordinated changes across many different tissues simultaneously — something electrical impulses alone cannot achieve. For example, adrenaline prepares the entire body for fight or flight by affecting the heart, muscles, digestive system, and breathing rate at once.
Source: Chapter 6, Section 6.3 — Hormones in Animals
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Explanation
- The question has two parts: limitations (1 mark) and why chemical is better (2 marks) — answer both clearly.
- The key phrase from the textbook is: "if the body design relied only on electrical impulses via nerve cells, the range of tissues instructed would be limited." Use this idea directly.
- For the second part, stress that hormones travel through blood and reach all cells, enabling wide-ranging changes — the examiner looks for these keywords.
- Adrenaline as an example strengthens the answer and shows application.