Lewin's Genes XII: Chapter 18 Exam Questions With Verified Answers.

Lewin's Genes XII: Chapter 18 Exam Questions With Verified Answers. Basal transcription factors - answerTranscription factors required by RNA polymerase II to form the initiation complex at all RNA polymerase II promoters. Factors are identified as TF X, where X is a letter. Core promoter - answerThe shortest sequence at which an RNA polymerase can initiate transcription (typically at a much lower level than that displayed by a promoter containing additional elements). For RNA polymerase II, it is the minimal sequence at which the basal transcription apparatus can assemble, and it includes three sequence elements: the Inr, the TATA box, and the downstream promoter element (DPE). It is typically approximately 40 bp long. Start point - answerThe position on DNA corresponding to the first base incorporated into RNA. Enhancer - answerA cis-acting sequence that increases the utilization of (most) eukaryotic promoters and can function in either orientation and in any location (upstream or downstream) relative to the promoter. Silencer - answerA short sequence of DNA that can inactivate expression of a gene in its vicinity. Coactivator - answerFactors required for transcription that do not bind DNA but are required for (DNA-binding) activators to interact with the basal transcription factors. Housekeeping gene - answerA gene that is (theoretically) expressed in all cells because it provides basic functions needed for sustenance of all cell types. Heterogeneous nuclear RNA (hnRNA) - answerRNA that comprises nuclear transcripts made primarily by RNA polymerase II; it has a wide size distribution and variable stability. Carboxy-terminal domain (CTD) - answerThe domain of eukaryotic RNA polymerase II that is phosphorylated at initiation and is involved i