The most valid hypothesis for why the control of gene expression is more complex in eukaryotes than in bacteria is the most valid hypothesis for why the control of gene expression is more complex in eukaryotes than in bacteria is more complicated cell structures in eukaryotes require more complex gene regulatory mechanisms the larger number of genes in eukaryotes means that regulation is more complex the need to create many differentiated cell types in eukaryotes means that there must be many mechanisms to modulate gene expression the need to respond to environmental signals in eukaryotes is greater than that in prokaryotic cells