Authentic Classroom Explanation by IAS Monk

🦠 Q9. ACE2 and Viral Diseases

📌 Question
The term ‘ACE2’ is talked about in the context of:

(a) genes introduced in genetically modified plants
(b) development of India’s own satellite navigation system
(c) radio collars for wildlife tracking
(d) spread of viral diseases

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✅ Correct Answer: (d) Spread of viral diseases

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🧑‍🏫 Authentic Classroom Explanation by IAS Monk

From first principles to final option — the UPSC way.

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🔬 Concept First

For a virus to infect a human cell, it must bind to a specific receptor on the cell surface.

👉 ACE2 is such a receptor.

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🔍 Option-wise Elimination

• Option (a): GM plant genes ❌
  • ACE2 is a human enzyme, not a plant gene
• Option (b): Satellite navigation ❌
  • Completely unrelated to biology
• Option (c): Wildlife tracking ❌
  • Refers to GPS/radio technology, not enzymes
• Option (d): Spread of viral diseases ✅
  • ACE2 acts as the entry receptor for SARS-CoV-2

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🧬 What is ACE2?

• Angiotensin-Converting Enzyme 2
• Present on:
  • Lung epithelial cells
  • Intestinal cells
  • Blood vessels
• SARS-CoV-2 spike protein binds to ACE2 to enter cells

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🔍 Curiosity Raiser

Did you know?
The virus does not “break” into the cell — it tricks the cell into letting it in by mimicking natural binding molecules.

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🧠 Enrichment Notes (UPSC Lens)

• ACE2 role beyond COVID:
  • Part of blood pressure regulation
  • Involved in cardiovascular and renal systems
• Why ACE2 matters in severity:
  • Higher ACE2 expression → higher susceptibility
• Common UPSC Trap:
  • Confusing ACE2 (enzyme) with virus itself (❌)
• Exam Value:
  • High-relevance current affairs linked to core biology

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🪶 IAS Monk Closing Whisper

In pandemics, the smallest doorway decides the fate of millions.