📘Q.5 IAS Prelims 2021 — GS | Science & Technology | Culturing Microorganisms
Authentic Classroom Explanation by IAS Monk
🧫 Q5. Culturing Microorganisms
📌 Question
Consider the following:
- Bacteria
- Fungi
- Virus
Which of the above can be cultured in artificial/synthetic medium?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
✅ Correct Answer: (a) 1 and 2 only
🧑🏫 Authentic Classroom Explanation by IAS Monk
From first principles to final option — the UPSC way.
🔬 Concept First
To be cultured on an artificial or synthetic medium, an organism must be able to carry out metabolism independently.
👉 This single principle cracks the entire question.
🔍 Statement-wise Analysis
1. Bacteria
✔️ Correct
- Independent cellular organisms
- Can grow on nutrient agar, broth, etc.
- Form visible colonies
2. Fungi
✔️ Correct
- Eukaryotic organisms with their own metabolic machinery
- Cultured on media like potato dextrose agar
3. Virus
❌ Incorrect
- Viruses are acellular
- Lack metabolic machinery
- Require a living host cell to replicate
- Cannot grow on artificial media alone
🔍 Curiosity Raiser
Did you know?
Viruses blur the line between living and non-living — outside a host, they are biologically inert, almost crystal-like.
🧠 Enrichment Notes (UPSC Lens)
- Key Distinction:
- Living cells → can be cultured independently
- Viruses → obligate intracellular parasites
- How viruses are grown in labs:
- Tissue cultures
- Embryonated eggs
- Living animal models
- Common UPSC Trap:
- Assuming viruses are “microorganisms” like bacteria (❌)
- Exam Value:
- Tests understanding of cellular organisation, not definitions
🪶 IAS Monk Closing Whisper
Life begins where metabolism begins.