The skeleton gives strength to the body. All vertebrates have an internal skeleton made of bones. These are mammals, birds, reptiles, amphibians, and fish. There are also animals with an external skeleton, which is a kind of shell. Insects, crabs, and some other animals have that.
When a human is born, its skeleton has just over 300 bones. By the time he grows up, there will only be a little over 200 bones left. Some bones grow together. It also depends on how you count. This is especially in the feet because there are many small bones there.
A skeleton must be held together. This work is done by ligaments and muscles. Without them, a skeleton would fall apart. But cartilage is also involved. For example, they hold the ribs together at the front.
Skeletons are important for archaeology. The bones are what remains of humans the longest. Scientists can find out a lot from the skeletons: Approximately how old the person was, whether it was a man or a woman, whether they had certain diseases, and much more.
With the help of old skeletons from the earth, doctors can also tell whether there were good doctors in a people. You can see whether a broken bone has healed properly or whether the two bone parts are at an angle.