Question

Some desert plants have very small leaves whereas some others have only spines. How does this benefit the plants?

Answer 1

Desert is one of the maximum dried land regions in the world that gets little or no precipitation annually. It is a land with very much less annual rainfall measured much less than $50{\text{ }}cm$ per year. Desert surroundings are the driest surroundings of the earth and that is why it has much less flora and much less variety of life. It is one of the elements of the terrestrial surroundings. The flora and animals of the barren region surroundings have mastered the artwork of survival in harsh conditions. A barren region surroundings largely without any rainfall or precipitation.

Complete answer:
In deserts due to high temperature and very little availability of water, every organism tries its best to preserve water for its body metabolism. The same is the case with desert plants.
Loss of water due to transpiration in plants is a major problem. Transpiration is a process by which plants release water through stomata on leaves.
Hence, in order to prevent loss of water due to transpiration desert plants usually have smaller leaves or have thorns or spines.
This helps the desert plants to survive in harsh and adverse climates of desert with water scarcity.

Note:
Xerophytes thrive in dry intense environments. Deserts are the commonest environments where we can find xerophytic plants like cacti, opuntia, acacia etc. Xerophytes plants show adaptations to absorb the most amount of moisture from the soil. Certain adaptations shown by xerophytes include shorter leaves, presence of spines, succulent stems, deeper roots etc.