Why are leaves modified into spines in prickly pear?

Leaves are modified into spines in

Leaves are modified into spines in

Stipules are modified into spines in

Leaves become modified into spines in :-

Leaves become modified into spines in :-

Leaves become modified into spines in :-

Bulb is modified

In Cacti, leaves are modified into

Xerophytes have their leaves modified to spines or reduced in size. Explain.

Assertion :- In some xerophytic plants stem becomes green , flat,leaf like and leaves are modified into spines . Reason :-In xerophytic areas rate of transpiration is high , so plants develop various adaptions to minimize transpiration.