Which of the following leaf modifications occur(s) in the desert areas to inhibit water loss? 1. Hard and waxy leaves 2. Tiny leaves 3. Thorns instead of l

1. A. 2 and 3 only
2. B. 2 only
3. C. 3 only
4. D. 1, 2 and 3

Answer: D

Explanation

These are plants growing in extreme dry conditions throughout the year. For example, plants growing in deserts (psammophytes), on rock (lithophytes) or alpine plants growing above 14000 feet altitude. Xerophytes Adaptations 1. Conservation of Water Modifications (a) Leaves few or absent or represented by spines only (b) Petiole modified into leaf like structure (c) Stem reduced, branching sparse (d) In some cases stem flattened, leaf like, green, photosynthetic in nature Thick, fleshy and succulent leaves as well as stem 2. Storage of Water ModificationsThick, fleshy and succulent leaves as well as stem 3. Prevention of loss of water by transpiration Modifications (a) Intercellular spaces reduced (b) Spongy parenchyma/ palisade parenchyma present (c) Stomata on lower surface, sunken in stomatal pits (d) Leaves needle like (e) Thick cuticle on leaf surface 4. Prevention of excessive heat Modifications (a) Leaves covered with dense hairs; (b) Leaf surfaces shiny or glaborous (c) Leaf blade remains rolled during the day 5. Efficient mechanism of water absorption Modifications (a) Long and profusely branched roots (b) Dense root hairs (c) Well developed xylem