Final answer:
In prokaryotes, promoters can vary widely across genomes, but there are conserved elements such as the -10 and -35 regions. These regions have specific consensus sequences that are recognized by sigma factors to initiate transcription.
Step-by-step explanation:
In prokaryotes, promoters vary widely across different genomes. However, there are a few conserved elements in many species, such as the -10 and -35 regions upstream of the initiation site. The -10 region has the consensus sequence TATAAT, while the -35 region has the consensus sequence TTGACA. These consensus sequences are recognized and bound by sigma factors (♂ -factors) to initiate transcription.