Prokaryotic transcription initiation closes with the release of short RNA polymers of roughly what length?

1. Several phosphodiester bonds are made once the promoter opens, but the first products are discarded. 2. These abortive transcripts are polymers of approximately 10 nucleotides that are made and released. 3. Their release marks the end of the initiation phase. 4. Forty is the elongation rate in nucleotides per second, so that number belongs to the next phase. 5. Two hundred is the approximate length of a eukaryotic poly-A tail, added long after this step. 6. Three is the size of a codon and has nothing to do with abortive products. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 15 "Genes and Proteins", section 15.2 Prokaryotic Transcription_