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Which of the following statements best defines the term operon?
What molecule binds to promoters in bacteria and transcribes the coding regions of the genes?
What is allosteric regulation?
Under which conditions are the lac structural genes expressed most efficiently?
What happens to the expression of the lacI gene if lactose is not available in the cell?
What is the function of the lacZ gene?
True or false? The mechanism by which glucose inhibits expression of the lac structural genes is known as catabolite stimulation, whereas the mechanism by which lactose stimulates expression of the lac structural genes is known as allosteric regulation.
The process by which lactose binds to the lac repressor and inactivates it by causing it to change shape is known as allosteric regulation. However, the process by which glucose causes cAMP levels in the cell to drop, thereby preventing CAP from stimulating expression of the lac structural genes, is known as catabolite repression.
The operon model of the regulation of gene expression in bacteria was proposed by _____.
In the presence of a regulatory protein the lac operon is _____.
Why is the lac operon said to be an inducible operon?
Which statements about the modification of chromatin structure in eukaryotes are true?
Some forms of chromatin modification can be passed on to future generations of cells.
Acetylation of histone tails in chromatin allows access to DNA for transcription.
Acetylation of histone tails is a reversible process.
DNA is not transcribed when chromatin is packaged tightly in a condensed form.
Methylation of histone tails in chromatin can promote condensation of the chromatin.
Which statements about the regulation of transcription initiation in these genes are true?
The fantasin gene will be transcribed at a high level when activators specific for control elements A, B, and C are present in the cell.
Control elements C, D, and E are distal control elements for the imaginin gene.
Both the fantasin gene and the imaginin gene will be transcribed at high levels when activators specific for control elements A, B, C, D, and E are present in the cell.
What is the event that IMMEDIATELY follows the last event of this animation?
Which of these directly bind(s) to the promoter?
RNA processing is indicated by the letter _____.
Which of the following processes is NOT indicated by the label A, B, C, D, or E?
The nuclear membrane's role in the regulation of gene expression involves _____.
Protein-phosphorylating enzymes' role in the regulation of gene expression involves _____.
In humans, the hormone testosterone enters cells and binds to specific proteins, which in turn bind to specific sites on the cells' DNA. These proteins probably act to do what?
It is possible for a cell to make proteins that last for months; hemoglobin in red blood cells is a good example. However, many proteins are not this long-lasting; they may be degraded in days, hours, or even minutes. What is the advantage of short-lived proteins?
miRNAs can control gene expression by what action?
Which of the following would be most likely to lead to cancer?
All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?
If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then
Which of the following is an example of post-transcriptional control of gene expression?
What would occur if the repressor of an inducible operon were mutated so it could not bind the operator?
Within a cell, the amount of protein made using a given mRNA molecule depends partly on
Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells?
Which statement(s) about inducible operons is/are correct?
Which statement(s) about repressible operons is/are correct?