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Prelims 2018 paper

UPSC CSE Prelims 2018 · Question 2 · Biodiversity, plants & animals

Which of the following leaf modifications occur(s) in the desert areas to inhibit water loss?

Prelims 2018 · Q2

Biodiversity, plants & animals Easy

Which of the following leaf modifications occur(s) in the desert areas to inhibit water loss?

  1. 1.Hard and waxy leaves
  2. 2.Tiny leaves
  3. 3.Thorns instead of leaves

Select the correct answer using the code given below:

Answer & explanation

Answer: (d) 1, 2 and 3

All three are ways in which dry-area plants cut water loss through transpiration. A waxy coat seals the surface, small leaves expose less evaporating surface, and thorns or spines replace leaves almost entirely.

  • ✓ 1. A thick, waxy cuticle on hard leaves slows the escape of water vapour; plants of very dry habitats often have such a coat.
  • ✓ 2. Small leaves have less surface from which water can evaporate and heat up less in the sun.
  • ✓ 3. In plants such as cacti the leaves are reduced to thorns or spines, so the plant loses very little water through leaves at all.

Remember · Desert (xerophytic) plants save water with waxy coats, small leaves, thorns/spines, deep roots and fleshy water-storing stems.

Sources

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·

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