Final answer:
It is true that promoter-specific transcription factors, such as Sp1 or NF1, are essential for assembling the transcription initiation complex in eukaryotic cells, involving in particular the binding of RNA polymerase II to the promoter region of genes.
Step-by-step explanation:
The statement that promoter-specific transcription factors, such as Sp1 or NF1, are required for the construction of the transcription initiation complex in eukaryotic cells is true. These factors, also known as basal transcription factors, are pivotal in assembling a complex on the DNA template which subsequently recruits RNA polymerase II for the transcription initiation. This set includes various TFII components, where TFIID with the TATA-binding protein is especially significant. Regulatory DNA sequences like the TATA box within eukaryotic promoters are recognized and bound by these transcription factors, facilitating the coordinated unwinding of DNA and initiation of RNA synthesis.
Although promoter-specific transcription factors are essential for constructing the initiation complex, elements like enhancers and silencers are not strictly required for transcription initiation but rather influence the frequency and efficiency of transcription. However, the presence of histones and the complex eukaryotic cellular machinery distinguishes the eukaryotic process of transcription initiation from that of prokaryotes, which is simpler and requires less protein machinery.