Answer: Human bones are hard, calcified structures with caverns that hold the living bone cells. The hardness of the bone helps to protect it, but all bones are also surrounded by a living membrane called the periosteum. When a bone breaks, it is the periosteum that produces new bone cells to repair the break. The bone must be set quickly or else it will heal as it is, and there will be deformity, because the periosteum immediately receives chemical signals that the bone has been broken and begins the repair process. It is imperative that the bone be set correctly to insure that the bone heals properly.
Answer: The bones in a human body are growing in diameter through theprocess of appositional growth. While, bones are growing longer inlength in the epiphyseal plate where cartilage is formed andossified.
Answer: Evolutionary seen, it all started with the chorda dorsalis (which we only have when we are foetusses and disappear in time) which would be surrounded by a layer of Cartilage (the same as your ears), by time the animals grew a cranium and multiple other cartilage bones which all had their function (as they were fish, they got their fins). Eventually to become better resistant to the world, the cartillage changed in real bone (full of Ca), and as those fish became Tetrapodamorpha, the fins became cluttering together to become what you see now as your legs and arms. Conclusion, all bones look different, because they all had/have their function (the past term as because eg the stuit is completely useless)