Question

levels of organization
put the following in their correct order of complexity (from simplest to most complex, with 1 being the simplest and 5 being the most complex)?
white blood cell (cell)
central nervous system (organ system)
the heart (organ)
human (organism)
epithelium (tissue)

Explanation:

In biological organization, cells are the basic unit. Tissues are groups of similar cells. Organs are made up of different tissues. Organ - systems are groups of organs working together. Organisms are made up of organ - systems. A white blood cell is a cell. Epithelium is a tissue. The heart is an organ. The central nervous system is an organ - system. A human is an organism.

Answer:

White blood cell (cell): 1
Epithelium (tissue): 2
The heart (organ): 3
Central nervous system (organ system): 4
Human (organism): 5