May exist singly as unicellular organisms or as subunits of multicellular organisms. The invention of the microscope led to the discovery of the cell and the formulation of the cell theory. All living forms are composed of cells. Though structurally different, eukaryotic and prokaryotic cells have many similarities, especially in their chemical processes. There is a relationship between an organism's structure and how it works.
Form fits function.
Organisms interact with their environment, which includes other organisms as well as abiotic factors. Both organism and environment are affected by the interaction between them. G. Regulatory mechanisms ensure a dynamic balance in living systems Regulation of biological processes is critical for maintaining the ordered state of life. Evolution, Unity, and Diversity A. Diversity and unity are the dual faces of life on Earth Biological diversity is enormous. Estimates of total diversity range from five million to over 30 million species.