What effect does tetracycline have on gene transcription in bacteria?

Tetracycline is an antibiotic that primarily functions by interfering with the process of protein synthesis in bacteria. When tetracycline binds to the ribosomal subunit, it prevents the binding of aminoacyl-tRNA to the RNA-ribosome complex. This action disrupts the translation of mRNA into proteins.

In the context of gene transcription, the presence of tetracycline does not directly inhibit the transcription of genes; instead, it affects the subsequent translation of the genes into proteins. In particular, if antibiotic resistance genes are present, tetracycline would not prevent their transcription, allowing them to be transcribed into mRNA. However, the translation of those mRNA transcripts into proteins necessary for antibiotic resistance would be inhibited by tetracycline, as the antibiotic interferes with the function of the ribosome.

Therefore, the correct answer reflects that tetracycline allows the transcription of antibiotic resistance genes to occur, even though it inhibits the translation of the proteins those genes encode, which is critical for the bacterium's survival in the presence of the antibiotic. This distinction clarifies why the correct choice highlights the ability of tetracycline to enable transcription while simultaneously impacting the translation process.