The<unk>  is of great interest to biologists because the three known varieties of<unk>  (eukaryotic, bacterial, and archaebacterial) each represent an extremely sophisticated cellular structure that requires the interaction of many different and finely-tuned systems to function correctly.
Evolution of flagella
Carrier generation and recombination
Bacterial conjugation
Gene expression
Signal transduction
Gene regulatory network
Biological life cycle
Cell signaling