🧷 Authentic Classroom Explanation by IAS Monk

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📌 The Question:

‘Aerial metagenomics’ best refers to which one of the following situations?

(a) Collecting DNA samples from air in a habitat at one go
(b) Understanding the genetic makeup of avian species of a habitat
(c) Using air-borne devices to collect blood samples from moving animals
(d) Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies

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✅ Answer: (a) Collecting DNA samples from air in a habitat at one go

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🧑‍🏫 Classroom Explanation:

Metagenomics is the study of genetic material recovered directly from environmental samples, without isolating and culturing individual organisms. When this approach is applied to air samples, it is called aerial metagenomics.

Living organisms continuously shed genetic material into their surroundings through:

• Breath
• Skin cells
• Saliva
• Hair, feathers
• Faeces and secretions

This genetic material, known as environmental DNA (e-DNA), remains suspended in air as microscopic particles.

🔹 Option-wise logic:

• Option (a) is correct ✅
  Aerial metagenomics involves collecting airborne e-DNA from a habitat in a single sampling effort, allowing researchers to assess biodiversity without physical capture.
• Options (b), (c), and (d) ❌
  These involve targeted biological sampling or drone-based collection, which are not metagenomics, as metagenomics focuses on community-level genetic sampling from the environment itself.

Hence, option (a) is correct.

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🔍 Curiosity Raiser:

🌬️ Can you identify animals without seeing them — just by the air they breathe?
Aerial metagenomics says yes.

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📚 Enrichment Notes (UPSC Edge):

• Aerial e-DNA can help:
  • Monitor endangered species
  • Track invasive organisms
  • Study biodiversity in inaccessible regions
• It is non-invasive, fast, and ecosystem-wide
• Increasingly used in wildlife conservation and climate biology

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🧘 IAS Monk Whisper:

🍃 Nature speaks even when silent — science just learns to listen better.