Defense. Predators leave it alone, so it lives and grows up to have more baby porcupines.
The spines help a porcupine to survive as it makes it difficult for another animal to eat it or attack it
A porcupine has spines as its defences.
Their spines
Its spikes, called quills ; this defensive adaptation protects the docile porcupine from predators.
If you mean spinal columns, yes pandas have them. If you mean prickly spines, such as the porcupine or hedgehogs have, the answer is no.
Quills
Sea urchins do NOT shoot there spines. They can simply let them pop out (sort of like a porcupine). Most people make this mistake... neither a porcupine or sea urchin SHOOT there spines. They do harden and stick out farther but they DO NOT SHOOT THEM!
no they are not poisonous but they are dangerous
Porcupines have quills.
That depends on which kind of spines you mean. Giraffes are vertebrates. That means that they have spines, as in a backbone. They do not have spines as in sharp pointed protrusions like a porcupine has.
cells are an organism's basic units of structure and function
The spines are an effective deterrent to herbivores, but also protect the plant stem. The spines increase the surface area available to collect moisture, an additionally help reflect the sun away from the stem and lower the stem temperature.