Question

Which of the following is the major adaptation for a plant to survive in the xerophytic conditions?
A. Long taproot
B. Lack of stomata
C. Spines
D. Stipular leaves

Answer 1

Xerophytic conditions are water-scarce conditions that are hot and have less or no precipitation. Plants that are the inhabitant of such conditions are called xerophytic plants. Xerophytic plants adapt by developing features such that they do not lose water to the surroundings.

Complete answer: The desert ecosystems are harsh survival habitats. Hot and dry conditions induce plant and animal species inhabitant in deserts to undergo certain adaptation to survive. Plants are very versatile organisms and develop several favorable adaptations to survive.
-The water-scarce conditions or xerophytic conditions stimulate the plant species to modify their root, stem, and leaf systems to take less surface area and thus reduce transpiration. Many of the xerophytic plants like cactus develop modifications namely spikes, swelled storing stems, etc.

To know various other major adaptations acquired by plants to survive in xerophytic conditions let us understand each modification in detail.
-Long taproots are those that have a single main root fiber in a straight down manner having other secondary root hair originating from it. The long tap roots allow the xerophytic plants to absorb water from the deeper levels of soil as the water is present in deep layers of soil in xerophytic conditions. These roots are 7 to 10 meters long and are much bigger than the plant itself.
-Lack of stomata is only seen in liverworts among land plants. The stomata provide the essential function of gaseous exchange in plants through leaves, thus it is an important part of the plant. The xerophytic plants do not lack stomata but have a waxy layer over the leaves that reduce the rate of transpiration.
-Spines are the modifications of leaves that are made to reduce the surface area of the leaves so that less evaporation of water takes place. Also, spines prevent animals from eating that plant.
-Stipules are outgrowths situated on either side of the base of the leaf stalk. These are generally seen in gymnosperms. These are a characteristic feature of all flowering plants. They are not present in xerophytic plants.
Therefore, the right answer is options A and C.

Note: The cactus is the most common example of xerophytic plants. They have a swollen body that is storing a type of stem that stores water in it. Also, it is covered in spines that prevent water loss. The cactuses vary greatly in their size and shapes. But they are the most suitable survivors of the desert ecosystems.