Topic Symbiosis
Asked 7 times across 3 UPSC exams over 35 years (1990–2025), peaking in 2013.
Key insights
- Most tested in CSE — 5 of 7 PYQs
- Most asked in 2013
- Recurs across 7 years (1990–2025)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1990 → CISF 2024 → GEO 2025
How the concept evolved
Rising — more than half its appearances (4 of 7) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
GEO2025
Which of the following associations is/are example/examples of mutualism?
- Mycorrhizae : Fungi and roots of higher plants
- Lichens : Fungi and photosynthetic algae
- Pollination : Mustard flower and honeybees
Select the correct answer using the code given below.
- A 1 only
- B 2 and 3 only
- C 1, 2 and 3 ✓
- D 1 and 3 only
✓ Correct answer: (C)
Environment & Ecology › Ecology & Ecosystems
CISF2024
Lichens represent the symbiotic relationships between algae and fungi. The algae component present in lichen is best known as
- A mycobiont
- B phycobiont ✓
- C prion
- D symbiont
✓ Correct answer: (B)
Science & Technology › Biology & Health
CSE2022
Certain species of which one of the following organisms are well known as cultivators of fungi?
- A Ant ✓
- B Cockroach
- C Crab
- D Spider
✓ Correct answer: (A)
Environment & Ecology › Ecology & Ecosystems
Study how UPSC repeats — not just the papers
₹199 / 1 year · Founding Member
Full access unlocks the three things no PYQ PDF gives you:
① Cross-exam learning — see the same idea recur across CSE, CAPF, CDS and NDA.
② Topic evolution — how each idea is framed, year by year.
③ Question intelligence — every PYQ + answer, linked to related concepts and similar questions.
e.g. Round Table Conference: CDS 2017 → CSE 2017 → … → CAPF 2024
15 days free, no card required — then ₹199 for 1 year.
Start your 15-day free trial →