Edith Forlin, age 13, of Niagara Falls, Ontario, Canada, for her question:

Do thorns help roses in any way?

In the world of nature, there is a good reason for just about everything. Porcupines have prickles to protect them from their enemies, the eagle has claws to catch his prey. The various plants also have special features for definite purposes. For example, cactuses are famous for their prickles. They live in arid regions where water is more precious than gold    and most cactuses have secret pockets of this precious stuff inside their fleshy tissues. The prickles serve to discourage thirsty desert animals from robbery.

Rose plants, even the wild species, need lots of nutrients to produce their lavish flowers. And their basic food is manufactured by their greenery. If a rose had no prickles, most likely its leaves would be nibbled by rabbits and munched by passing goats. The plant's food production would be reduced and so would its roses. The prickliest rose bushes are the ones most likely to survive and produce the healthiest flowers.