Question

What is false regarding DNA regulatory sequences?

A)In eukaryotes, they are often found to fully function independently of any other protein.

B)They are used to turn genes on or off.

C)The sequences can range from 10 nt sequences to 10,000 nt sequences.

D)They are able to integrate a wide variety of signals into a command that will regulate initiation of transcription of a gene.

E)They are recognized by proteins referred to as Transcription regulator

Answer 1

Answer: DNA regulatory sequences

A. False. There are proteins called transcription factors which bind to specific sequences and may act as activator or repressor

B. True. When the activator transcription factor binds to the sequence, the RNA polymerase forms a complex binding to the transcriptional initiation region (promoter), thus initiating transcription and the gene is turned on. When the repressor binds to the speciifc sequence, it prevents the formation of RNA polymerase productive complex and the gene is turned off.

C. False. The sequence is usually 100 to 100 bp in length and may be located 10 to 10,000 bp upstream or downstream from a promoter

D. True. In order to initiate transcription they integrate a variety of signals into a command as described in B

E. True. Transcription regulators can be activator or repressor