A hard structure that is part of an animal's internal skeleton.

• bone

• skeleton

• joint

• muscle

All of the bones or other structures that provide support to an animal's body.

• bone

• skeleton

• joint

• muscle

A place where two or more bones come together.

• bone

• skeleton

• joint

• muscle

A structure that contracts and relaxes to produce movement.

• bone

• skeleton

• joint

• muscle

A lightweight, flat structure that forms an outside covering of a bird's body.

• feather

• fin

• scale

• exoskeleton

A flattened structure on the body of a fish that helps the fish move, steer, and balance.

• feather

• fin

• scale

• exoskeleton

A flattened stiff plate that forms an outer covering on a fish or reptile.

• feather

• fin

• scale

• exoskeleton

A type of skeleton on the outside of some animals’ bodies. It is a hard cover. Many invertebrates, like insects, have exoskeletons.

• feather

• fin

• scale

• exoskeleton

• bone

• skeleton

• joint

• muscle

• bone

• skeleton

• joint

• muscle