143. Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss? (2013)

1. Hard and waxy leaves
2. Tiny leaves or no leaves  
3. Thorns instead of leaves 

Select the correct answer using the code given below: 

(a) 1 and 2 only 

(b) 2 only 

(c) 1 and 3 only 

(d) 1, 2 and 3 

Answer: (d) 

Option (d) is correct: Desert plants lose very little water through transpiration. The leaves in desert plants are either absent, very small, or they are present in the shape of spines. This helps in reducing loss of water from the leaves through transpiration. Plants growing in extreme dry conditions throughout the year adopted thorns instead of leaves to prevent loss of water. Photosynthesis in these plants is usually carried out by the stems. The stem is also covered with a thick waxy layer, which helps to retain water. Most desert plants have roots that go very deep into the soil for absorbing water.