Question

Why cacti have spines on their body?​

Answer 1

Answer:

Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis.

Answer 2

Answer:

Cacti have spines on their body to prevent the loss of water and to protect themselves from herbivores.

Hope it helps!