Question

Which part of the cactus is transformed into spine?

Answer 1

correct answer is leaf

Answer 2

Leaves of cactus are modified into spines.In xerophytic conditions where is a huge loss of water due to transpiration, leaves of cactus are completely transformed into spines .Even some of the plants do not have leaves retaining only spines(highly modified leaves).These modifications also helps plant defending against herbivores.  In place of leaves ,enlarged stems perform photosynthesis.