2. The different levels of structural organization that make up the body are the chemical level, the cellular level, the tissue level, the organ level, the organ system, and the organismal level. Their relationships can be explained by atoms combining to form molecules which associate to form organelles which make up cells, which in groups are tissues, two or more tissues is an organ, organs working together is an organ system and the complete organism makes up the organismal level.

3. The 11 organ systems in the body are the cardiovascular system which transports blood and carries oxygen, CO2 etc, the integumentary which forms the external body covering, skeletal which protects and supports body organs, muscular which allows manipulation of the environment, nervous which is the fast acting control system of the body, endocrine which are glands that secrete hormones that regulate processes, respiratory which keeps blood constantly supplied with oxygen, digestive which breaks down food, lymphatic which picks up fluid leaked from blood vessels, urinary which eliminates nitrogenous waste, and reproductive whose overall function is to produce offspring.