Which of the following is the correct order from most complex to simplest for the levels of organization in the human body?
a. cells, tissues, organs, organ systems
b. cells, organs, organ systems, tissues
c. organ systems, tissues, organs, cells
d. organ systems, organs, tissues, cells

A. cells, tissues, organs, organ systems

Cells when grouped form tissues, when group of tissues are formed together they make organs, some organisms skip from organs to organs systems to form an existing organism as a whole. Describing how is the cells group is the process of multiplication of cell or the so-called cell division, mitosis. This mechanism of each cell produces another cell that binds together and produces again, repeatedly, to be a larger system called now the tissue as explained earlier. How? Through cell division called, mitosis. Excerpt meiosis –cell division specifically in the sex cells.

A.CELLS,TISSUES,ORGANS,ORGAN SYSTEM

The process that fuels our sun and allows it to give off that much energy is called nuclear fusion.

Crossing over creates new combinations of genes in the gametes that are not found in either parent contributing to genetic diversity