Human cells need oxygen for respiration. What system of the body is responsible for transporting an oxygen molecule to different locations throughout the body?

The skeletal system provides structural support and protection for the body's organs. It also serves as the body's primary calcium storage site and houses the bone marrow, which produces blood cells. However, it does not actively transport oxygen molecules to different parts of the body.

The lymphatic system is part of the immune system and is involved in defending the body against disease. It helps maintain fluid balance in the body by collecting excess fluid and returning it to the bloodstream. While it does transport lymph—a fluid containing white blood cells and sometimes other substances—throughout the body, it does not transport oxygen.

The respiratory system is responsible for gas exchange—taking in oxygen from the environment and expelling carbon dioxide. While it does take in oxygen and expel carbon dioxide, it does not transport these gases throughout the body. This function is performed by the circulatory system.