UPSC Prelims 2025 Q39: Science & Technology – Botany
- (a) Only two
- (b) Only three
- (c) Only four
- (d) All five
Answer: (b) Only three
Explanation
Plant Description Matching:
| Plant | Description Given | Correct? | Why |
|---|---|---|---|
| Cassava (Manihot esculenta) | Woody shrub | TRUE | Cassava is a perennial woody shrub - it forms lignified (wood-like) stems that persist above ground. |
| Ginger (Zingiber officinale) | Herb with pseudostem | TRUE | Ginger is a herbaceous plant whose aerial shoots are formed by overlapping leaf sheaths - this is a classic pseudostem (not a true stem). |
| Malabar spinach (Basella alba) | Herbaceous climber | TRUE | Malabar spinach is a succulent-stemmed herbaceous climber - it twines around supports and lacks woody tissue. |
| Mint (Mentha spp.) | Annual shrub | FALSE | Mint is a perennial herb, not an annual and not a shrub. It spreads via underground stolons/runners and re-grows each season. |
| Papaya (Carica papaya) | Woody shrub | FALSE | Papaya is a large herb (or arborescent herb) - its trunk is soft and hollow, lacking true lignified (woody) tissue. It is single-stemmed, NOT a shrub. |
Correct pairs: I (Cassava), II (Ginger), III (Malabar spinach) = Only three.
Key distinction — Pseudostem vs True Stem:
A pseudostem is NOT a real stem — it is a bundle of tightly rolled leaf bases/sheaths stacked on top of each other.
Banana and ginger are the two most famous pseudostem plants in UPSC.
Key distinction — Woody vs Herbaceous:
Woody plants have lignin in their cell walls → hard, persistent stems (cassava, trees, shrubs).
Herbaceous plants have soft, non-lignified stems → die back seasonally (ginger, mint, malabar spinach, papaya).
Answer: (b) Only three.
Why each option is right or wrong
- (a) Incorrect. 'Only two' would be correct if one of the three valid pairs (Cassava, Ginger, Malabar spinach) were wrong. All three are correctly described.
- (b) CORRECT. Pairs I (Cassava = woody shrub), II (Ginger = herb with pseudostem), and III (Malabar spinach = herbaceous climber) are all accurately described. Mint is perennial (not annual) and papaya is herbaceous (not woody).
- (c) Incorrect. 'Only four' would require either Mint or Papaya to be correctly described. Mint is a perennial herb (not an annual shrub) and Papaya has a soft hollow stem (not woody).
- (d) Incorrect. All five cannot be correct because Mint (perennial herb, not annual shrub) and Papaya (herbaceous/soft stem, not woody shrub) are clearly mismatched.
Key point
Pseudostem = rolled leaf sheaths (Banana + Ginger). Papaya = herbaceous, NOT woody. Mint = perennial, NOT annual.
Remember
Papaya trunk = soft and hollow = NOT woody. Ginger aerial shoot = pseudostem (leaf sheaths). Mint = perennial herb, not annual.
Common mistakes
- Confusing Papaya as a woody tree — it looks tree-like but its trunk has NO lignified (woody) tissue.
- Not knowing that Ginger has a pseudostem — students often associate pseudostems only with Banana.
- Calling Mint an annual — Mint is strongly perennial and spreads via stolons, surviving winters underground.
Exam tip
Pseudostem plants: Banana + Ginger (both monocots with leaf-sheath aerial shoots). Papaya = always herbaceous — the single most common wrong assumption about it. Mint = always perennial.
Sources
- NCERT Class XI — Biology (Chapter 5: Morphology of Flowering Plants)
- NCERT Class XI — Biology (Chapter 7: Structural Organisation in Plants)