UPSC Prelims 2023 Q69: Science & Technology – Biotechnology & Genetics
'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
Answer: (a) Collecting DNA samples from air in a habitat at one go
Explanation
Aerial metagenomics — reading DNA from the air
Metagenomics studies all the DNA in an environmental sample at once.
Aerial metagenomics collects airborne DNA (air eDNA) to find which plants, animals and microbes live in a habitat.
| Step | What happens |
|---|---|
| Sampling | Air is pumped through filters that trap fur, skin cells, pollen and spores |
| Sequencing | All the DNA on the filter is read together |
| Matching | Sequences are compared with DNA databases to name species |
Uses:
| Use | Example |
|---|---|
| Biodiversity surveys | 2022 zoo studies (London, Copenhagen) identified dozens of animal species from air alone |
| Disease watch | Tracking airborne pathogens |
| Allergy forecasts | Measuring pollen and fungal spores |
Answer: (a) Collecting DNA samples from air in a habitat at one go.
Why each option is right or wrong
- (a) CORRECT. Aerial metagenomics captures DNA from the air of a habitat in a single sampling.
- (b) Incorrect. It is not limited to birds; it detects DNA from all kinds of organisms.
- (c) Incorrect. It does not collect blood samples; it uses air filters.
- (d) Incorrect. Collecting physical samples from land and water by drone is not metagenomics of air.
Key point
Aerial metagenomics = sequencing all DNA trapped from air (air eDNA) to survey a habitat's species at once.
Remember
Aerial metagenomics reads DNA collected from the air of a habitat.
Common mistakes
- Reading 'aerial' as birds and choosing the avian option.
- Thinking it needs drones or devices on animals; it uses simple air filters.
- Confusing metagenomics (many organisms at once) with genomics (one organism).
Exam tip
Meta = all at once; aerial = from the air. Put the two together and option (a) follows.
Sources
- Clare et al. (2022), Current Biology — Measuring biodiversity from DNA in the air
- NCERT Class XII — Biology, Ch 11 (Biotechnology: Principles and Processes)