Consider a Cis-Regulatory Enhancer Sequence in the Escherichia Coli Chromosome

question 54

Multiple Choice

Consider a cis-regulatory enhancer sequence in the Escherichia coli chromosome that is located thousands of nucleotide pairs upstream of the gene that it regulates. If the regulatory sequence is mutated to become nonfunctional, the introduction of the wild-type enhancer on a plasmid fails to regulate the gene. This implies that …

• A) the regulatory sequence encodes a regulatory protein that binds near the promoter of the target gene and controls RNA polymerase binding.
• B) the regulation of the target gene involves looping out of the intervening DNA, and the promoter of the cis-regulatory sequence must be on the same chromosome.
• C) the regulatory sequence can bind directly to the RNA polymerase.
• D) the regulatory sequence cannot bind to a protein.

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Definitions:

Level Shift

A statistical term describing a sudden change in the mean level of a time series dataset.

Instability

The state of being prone to change, variation, or unpredictability, often in a way that is difficult to control or manage.

Cycle

A sequence of events that repeat in a regular and predictable pattern over time.

Type Error

Mistakes made in statistical hypothesis testing, specifically Type I error (false positive) and Type II error (false negative).