The fourth level of cell organization is the
tissue level
system level
organ level
organism level

The fourth level of cell organization is the organ level. The organ level is a structure composed of collections of tissues that perform specific functions in a living organism. Organs that are found in a human body are the heart, lungs, brain, pancreas, liver, among others. These organs perform specific functions and work in an interconnected manner for the human body to function well. When organs work together, they are called organ systems which are already the fifth level of cell organization.