How does the organ level of organization relate to cells and organ systems

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

Which anatomical plane is the only one that could not show both the sternal region and vertebral region

Amajor source of energy for your body comes from