Organisms composed of many SingleCells.  They compete for survival with SingleCells and other multicellular organisms. Cooperation between them is relatively infrequent, but usually occurs at some stages in their life and in some plays a major role in survival. The SingleCells, however, cooperate with the other SingleCells in the same organism almost all the time, giving up their autonomy in support of the survival of the assembly, which all share the same DNA. In a few cases, multicellular organisms have reached levels of cooperation that have been described as MetacellularOrganism''''''s by analogy.
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On earth they evelop by the GeneticCode