Question

Assertion :True xerophytes store water in the form of mucilage which helps to withstand prolonged period of drought. Reason: Vascular and mechanical tissues are well developed in true xerophytes.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is not correct but Reason is correct.

Answer 1

The correct option is D Assertion is not correct but Reason is correct.

Xerophytes are plants adapted to live in dry conditions. Common adaptations to reduce the rate of transpiration include:

• Well developed vascular and mechanical tissues to utilise maximum benefit from water stress conditions.
• Thick waxy cuticle that acts as a barrier to evaporation.
• Sunken stomata in pits in the epidermis trap moist air that reduces evaporation rate.
• Leaf rolled with stomata in the inner surface is covered in hairs that help trap moist air and reduce transpiration. In addition, a smaller surface area of leaf is exposed to the drying effects of the wind.
• Small leaves to reduce the surface area and hence the evaporating surface.
• Extensive shallow root systems allow quick absorption of large quantities of water when it rains.