Question

which shows three human body parts in order from the simplest level of organization to the most complex?
red blood cell → nervous system → bone tissue
nervous system → bone tissue → red blood cell
red blood cell → heart tissue → circulatory system
bone tissue → red blood cell → nervous system

Explanation:

The levels of organization in the human body from simplest to most complex are cell, tissue, organ, organ - system. A red blood cell is a cell. Heart tissue is a type of tissue. The circulatory system is an organ - system.

Answer:

C. red blood cell → heart tissue → circulatory system