Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss? Select the correct answer using the codes given below.

Answer: (d) 1, 2 and 3

All three reduce the surface through which water escapes.

Statement by statement

1. ✓ CORRECT A thick waxy cuticle waterproofs the leaf and cuts evaporation.

2. ✓ CORRECT Small leaves or none (the stem does photosynthesis) mean less surface to lose water from.

3. ✓ CORRECT Cacti turn leaves into spines — almost no transpiring surface, plus protection from grazers.

The idea

A plant loses water mainly through the tiny pores (stomata) on its leaves. A desert plant survives by offering less surface for that loss, and by sealing the surface it does have. All three changes in the question do one of these.

Thick waxy coat → seals the surface → Tiny or no leaves → less surface → Spines instead of leaves → almost no surface, and protection from animals → Green stem takes over photosynthesis

The trap

Some think thorns are only for defence. They also do the water job.

Also know

Desert plants are called xerophytes. Other adaptations: very deep roots (khejri), water stored in fleshy stems (cactus), pores sunk in pits, and CAM photosynthesis, where pores open only at night. Some desert plants avoid drought altogether by completing their life in a few weeks after rain.