Final answer:
Fingernails and toenails protect the fingertips and toes and enhance sensation, while bone marrow is vital for the production of blood cells. Both nails and hair contain keratin, providing strength and protection.
Step-by-step explanation:
Functions of Hair, Fingernails, and Bone Marrow
Fingernails and toenails are composed of dead cells filled with keratin, making them tough and flexible. They serve important functions, such as protecting the fingertips and toes from injuries and enhancing tactile sensation by acting as a counterforce when objects are handled. Furthermore, fingernails can be used as tools in daily activities.
The bone marrow, specifically the red bone marrow, plays a critical role in the body by being the primary site of hematopoiesis - the process of blood cell production. It generates red blood cells, white blood cells, and platelets, crucial components of the circulatory system.
Although hair was not fully addressed in the student's question, it is worth noting that hair also contains keratin and serves various functions such as acting as a filter, providing insulation, and aiding in the protection of the body.