Q. In cactus, the spines are the modified ____:
Answer: Leaves
Notes: Most cactus morphologists have concluded that cactus spines are modified leaves. They are wholly transformed leaves that protect the plant from herbivores, radiate heat from the stem during the day, and collect and let drip condensed water vapour during the cooler night.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 67 in 12. Morphology and Adaptations in Higher Plants in above course in App.