Which of the following is a characteristic of enhancer sequences in eukaryotic cells?
A)Enhancer function is dependent on recognition by a specific transcription factor.
B)They occur only upstream of the gene.
C)They can only be in one orientation.
D)Specific transcription factor binding at an enhancer inhibits transcription by reducting RNA polymerase II activity.

Question

Quizplus · Accepted Answer

Enhancer function is dependent on recognition by a specific transcription factor. Enhancers are cis-acting regulatory DNA sequences that can increase or decrease transcriptional activity of a gene, and their function depends on the specific transcription factor that binds to them.

Answer: B and C 
 Both B and C are incorrect because enhancer sequences can be located upstream, downstream, or even within introns of a gene, and they can be in either orientation relative to the gene.

Answer: D 
 D is incorrect because specific transcription factor binding at an enhancer can increase transcriptional activity by promoting RNA polymerase II activity, rather than inhibiting it.

Which of the Following Is a Characteristic of Enhancer Sequences