Which list shows three components of an organ system in order of least complex to most complex? red blood cell, heart, tissue. skeleton, bone, bone cell. muscle cell, muscle tissue, stomach. lung tissue, lung, circulatory system.

Muscle cell, muscle tissue and stomach.

Explanation: The organization of the body starts from the simplest cell to the complex organ.

The smallest structural and functional unit of the body is cell and the cells combine to form tissues and the tissue are arranged to from organ.

Here, the least complex component of the body is muscle cell and then muscle tissue and the final level of organization is Stomach.

b. the carbon cycle ensures living things have a source of hydrogen