Why is gene regulation necessary in the development of multicellular organism? use a specific example to support your argument

Gene regulation is necessary in the development of multi-cellular organisms because it is necessary to make sure certain things go where they are needed to go. Multi-cellular organisms have more organ systems, therefore depend on more cells to live. Cells have a memory; the genes a cell expresses and the way it behaves depend on the cell's past, as well as its present environment.

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