What is a skeleton?

The correct answer defines a skeleton as the frame of bones supporting a body. The skeleton serves as the structural foundation for vertebrate organisms, providing support and protection for the body’s organs. It consists of various bones that are connected by joints, contributing to the overall shape and stability of the organism while also allowing for movement facilitated by the muscular system.

Additionally, the skeleton plays a crucial role in protecting vital organs, such as the heart and lungs, which are contained within the ribcage. It also serves as a site for the production of blood cells in the bone marrow and the storage of minerals like calcium and phosphorus.

In contrast, the other options do not accurately describe what a skeleton is. Muscle tissue refers to the system responsible for movement, organs comprise functional units within the body, and the outer layer of skin relates to the integumentary system, none of which pertain to the skeletal framework. Each of these elements contributes to the body's functioning but does so in ways distinct from the support and structure provided by the skeleton.