Final Answer:
Translation can start while transcription is still in progress in bacteria due to the absence of a nuclear membrane, allowing simultaneous occurrence of both processes in the cytoplasm.
Step-by-step explanation:
Translation and transcription are the two primary processes involved in the expression of genes. In bacteria, unlike eukaryotic cells, there is no separation between the transcription of mRNA and translation of proteins by a nuclear membrane.
Bacteria lack a nucleus; their genetic material floats freely in the cytoplasm as a circular DNA molecule. Consequently, as the mRNA is being transcribed from the DNA, ribosomes can attach to the mRNA strand and initiate the translation process almost immediately.
The close proximity of DNA, mRNA, and ribosomes in the bacterial cytoplasm enables a more rapid and simultaneous occurrence of transcription and translation. This concurrent process expedites protein synthesis, allowing bacteria to efficiently produce proteins needed for various cellular functions without waiting for the completion of mRNA transcription.
This ability to start translation while transcription is ongoing is known as coupled transcription-translation. It's a characteristic feature of bacterial cells due to their simpler cellular organization compared to eukaryotic cells.
This simultaneous process aids bacteria in quickly responding to environmental changes by promptly synthesizing proteins required for adaptation or survival.