Which term refers to the death of the organism as a whole?

The term that refers to the death of the organism as a whole is somatic death. Somatic death signifies the cessation of all biological functions that sustain life, marking the end of life for the entire organism. This process involves the failure of the circulatory, respiratory, and neurological systems, leading to the irreversibility of life processes.

In contrast, viability relates to the ability of an organism to survive or function effectively, which is not applicable to the concept of death. Cellular death refers specifically to the death of individual cells, which can occur independent of the organism's overall life state, particularly in cases of injury or disease. Tissue necrosis involves the death of a specific group of cells within a tissue, often due to factors like lack of blood supply or infection, and does not encompass the organism as a whole.

Therefore, somatic death is the most accurate term when discussing the overall death of an organism, as it captures the complete cessation of life functions rather than focusing on individual cells or tissues.