What components make up the Basal Transcriptional Apparatus?

The Basal Transcriptional Apparatus is essential for the transcription of genes in eukaryotic cells, specifically those transcribed by RNA polymerase II. This apparatus is primarily composed of general transcription factors and RNA polymerase II. General transcription factors are a set of proteins that bind to specific DNA sequences, facilitating the assembly of the transcription machinery at the promoter region of a gene. They play a crucial role in recruiting RNA polymerase II and ensuring the correct initiation of transcription.

RNA polymerase II is the enzyme responsible for synthesizing messenger RNA (mRNA) from DNA templates. Together, the general transcription factors and RNA polymerase II form a complex that is necessary for the initiation of transcription. This interaction ensures that RNA polymerase is accurately positioned to transcribe the DNA into RNA.

In contrast to other choices, the options such as solely RNA polymerase II or primarily mRNA and tRNA do not encompass the full range of components essential for transcription initiation. Also, including transcription factors and siRNA overlooks the specific composition and function of the Basal Transcriptional Apparatus, as siRNA is involved in RNA interference and does not contribute directly to the transcription process. Thus, the correct response encompasses the key components vital for initiating transcription in e