Question

Comment upon the xerophytic adaptation in desert plants.

Hint:

Xerophytes survive in deserts by reducing water loss (spines, thick cuticle) and storing water (succulent tissues, CAM photosynthesis).

Answer 1

Xerophytes are plants that are adapted to survive in dry, arid environments such as deserts where water is scarce. They exhibit a variety of structural and physiological adaptations to minimize water loss and maximize water absorption. Important Xerophytic Adaptations: \begin{enumerate} \item Morphological Adaptations: \[\begin{array}{rl} \bullet & \text{Leaves are reduced to spines (e.g., cactus) to minimize transpiration.} \\ \bullet & \text{Stems become green and photosynthetic (phylloclade) to carry out photosynthesis.} \\ \bullet & \text{Thick cuticle and waxy coating on stems/leaves reduce water loss.} \\ \end{array}\] \item Anatomical Adaptations: \[\begin{array}{rl} \bullet & \text{Sunken stomata reduce direct exposure to dry air, thereby reducing transpiration.} \\ \bullet & \text{Water storage tissues (succulent parenchyma) store large quantities of water (e.g., Opuntia, Aloe).} \\ \bullet & \text{Well-developed vascular tissues help in efficient water transport.} \\ \end{array}\] \item Physiological Adaptations: \[\begin{array}{rl} \bullet & \text{CAM (Crassulacean Acid Metabolism) photosynthesis, where stomata open at night to minimize water loss.} \\ \bullet & \text{High osmotic pressure in cells enables absorption of water even from dry soil.} \\ \end{array}\] \end{enumerate} Summary: These adaptations allow xerophytic plants to conserve water, withstand prolonged drought, and thrive in extreme desert conditions.