Flies are arthropods, which don't have an internal skeletal system like we do. Instead they have an exoskeleton that provides the support for their bodies.
None. They all have exoskeletons that protect the fly's internal workings.
it helps them fly because their bones are lighter and its easier to fly with light bones. But birds with dense bones, such as penguins makes it impossible for them to fly
do fly's have backbons
Birds have hollow bones to help them fly.
Because they fly, there bones need to be hollow to cut down on there weight.
Birds have hollow bones that make them lighter so they can fly more easily.
Birds have hollow bones to help them fly. Solid bones would add to much weight and make it impossible to fly. They have crisscross structures to add support inside the bones.
they are light enough to fly
Birds have hollow bones to help them fly. Solid bones would add to much weight and make it impossible to fly.
Like birds, Pterodactylus and all other pterosaurs had many tiny air sacs in its bones. The air sacs lowered the density of the pterosaur's bones, thus increasing its weight and making it easier for it to fly.
People can't (or don't) fly since their bones are full of marrow, and to fly, their bones have to be empty, like a birds. Also, people would need wings. That is why i am getting surgery to get my bones cleaned out and working eagle wings patched on tome.
So that the bird is not too heavy to fly and to aid in the intake of oxygen as the bird breaths in flight.