Question

Why is leaf of cactus converted into spine?

Answer 1

they are converted into spine so that minimal transpiration takes place through leaf so as to conserve water as water is scarce in the region where cactus grows

Answer 2

●In deserts where cactus usually grows, there is scarcity of water.

●Also,due to high temperatures the rate of transpiration is very high.

●Thus to prevent water retention, leaves of cactus have been modified into spines( as surface area will decrease and in turn the rate of transpiration will also decrease).