Bones have a hard coating to protect the nerves, marrow and blood vessels located in the cavity,
Spiders do not have bones. They are arthropods, their soft tissues are contained inside a hard external coating called an exoskeleton.
soft you can bend and hard you can not
Seal's bones are hard.
Calcium makes bones and teeth strong as it is like the enamel coating your teeth and bones.
Periosteum
Spiders do not have bones. They have exoskeletons which is a hard outer shell.
Hard.
Mainly Diatoms
Yes bones are as hard as rock they can take up to 1,000 pounds of pressure
sweet
Because egg has calcium coating
No insect have bones. They have a hard outer covering, but no bones.