Function, Structure, and Types of RNA

If a scientist discovers a new virus that replicates using RNA polymerase with no proofreading capabilities, what would be the most likely consequence regarding its mutation rate?

Considering the role of RNA in protein synthesis, what would be the most immediate impact of a drug that selectively inhibits ribosomal RNA (rRNA) production?

In a scenario where a cell's DNA is damaged and cannot be directly transcribed, what compensatory mechanism involving RNA could potentially allow the cell to produce essential proteins?

During gene expression, a mutation occurs that introduces a premature stop codon in the mRNA sequence. What is the most likely outcome of this mutation at the protein level?

A researcher is studying a newly discovered prokaryotic organism and identifies a unique operon structure. This operon contains a gene that inhibits its own expression by encoding a regulatory RNA that binds to its own mRNA. What type of regulatory mechanism is this?

In a eukaryotic cell, how would the disruption of the spliceosome complex most directly affect gene expression?

If a mutation in a tRNA gene alters the anticodon sequence, what is the most likely direct consequence for protein synthesis?

A researcher discovers that a specific gene is transcribed at high levels in liver cells but is almost silent in brain cells. Which of the following mechanisms is most likely responsible for this tissue-specific gene expression?

Suppose a research team introduces a mutation in the gene encoding RNA polymerase in a bacterial cell. Which of the following outcomes would most directly support the hypothesis that the mutation affects the enzyme's ability to recognize promoter sequences?

Which of the following is NOT an example of post-translational modification that can affect the function of a protein involved in RNA processing?

A researcher is investigating the effect of a novel drug on eukaryotic translation. They observe that the drug inhibits the formation of the initiation complex but does not affect ribosome assembly or tRNA binding. What specific step in translation is most likely being targeted by this drug?

A scientist is studying a regulatory RNA molecule in a eukaryotic cell. They discover this RNA binds to a specific mRNA transcript, preventing its translation by blocking the ribosome binding site thereby inhibiting protein production. Which type of regulatory RNA is MOST likely responsible for this function?

During transcription in eukaryotes, a phenomenon known as 'attenuation' is observed. Which of the following scenarios would MOST likely lead to premature termination of the RNA transcript due to attenuation?

A certain eukaryotic gene contains a sequence in its promoter region that is bound by a transcriptional repressor protein when a specific metabolite is absent. However, when the metabolite is present, it binds to the repressor, causing the repressor to detach from the DNA and allowing transcription to occur. What type of regulatory mechanism is this?

If a cell were treated with a drug that inhibits the function of aminoacyl-tRNA synthetases, what would be the most immediate and direct consequence on protein synthesis?

A researcher is studying a particular gene in yeast and discovers that it is only transcribed when the cells are exposed to high temperatures (heat shock). Which of the following regulatory elements is most likely involved in controlling the expression of this gene?

Considering the central dogma of molecular biology, which of the following scenarios would MOST directly challenge the traditional understanding of information flow?

A geneticist is studying a newly discovered bacterial species. They find that a particular gene is transcribed, however, translation is blocked by a protein binding to the Shine-Dalgarno sequence (ribosome binding site) on the mRNA. What type of regulation is this?

How does the presence of a 5' cap and a 3' poly-A tail on eukaryotic mRNA molecules contribute to efficient protein synthesis?

A scientist is engineering a synthetic operon in bacteria. To ensure the operon is only transcribed when a specific inducer molecule is present, which regulatory component is absolutely essential to include?

A new drug is discovered that inhibits the activity of bacterial topoisomerases. What effect would this drug most likely have on bacterial transcription and replication?

What is the primary role of the TATA box found in the promoter region of many eukaryotic genes?

In a genetic experiment, a researcher introduces a mutation into the gene coding for a chaperon protein. How could this influence RNA processing and gene expression?

A scientist is studying a gene in eukaryotic cells and finds its expression is regulated by a silencer sequence located several thousand base pairs upstream of the promoter. How does this silncer most likely inhibit transcription of the gene?

A research team discovers a novel prokaryotic regulatory mechanism where an antisense RNA molecule base-pairs with a specific mRNA, leading to the degradation of the mRNA by cellular enzymes. What is the MOST direct effect of this process on gene expression?

During an experiment, a researcher discovers that a mutation in the 3' untranslated region (UTR) of a specific mRNA transcript in a eukaryotic cell leads to a significant increase in the amount of protein produced from that mRNA. What is the most likely explanation for this observation?

A researcher is studying a bacterial species where they identify a unique feature: the tRNA molecules lack the typical modifications found in other organisms. What would be the most likely effect of this deficiency on translation?

A scientist is studying the expression of a gene in liver cells. They notice the gene's mRNA has multiple different poly(A) tail lengths but the resulting protein is always the same. What could be the primary implication of this finding regarding gene regulation?

A researcher is investigating why a particular eukaryotic gene is expressed at very low levels, even though the gene has a normal promoter sequence and the necessary activators are present. Which of the following epigenetic mechanisms is most likely responsible for this low level of expression?

A scientist discovers that a particular mutation in yeast cells causes a significant increase in the rate of transcription termination at specific genes. Which protein would be most likely affected by this mutation?

A researcher is studying a novel eukaryotic gene and discovers that it produces two different protein isoforms (variants) from the same gene. What molecular mechanism BEST explains this observation?

A researcher is studying a bacterial operon responsible for the metabolism of a novel sugar. They find the operon is expressed only when the sugar is present and glucose is absent. What regulatory strategy is most probably by the bacterium to control this operon?

A scientist is studying a gene and discovers this gene in eukaryotic cells is regulated by an enhancer sequence located a considerable distance away from the promoter. How is this possible?

A graduate student is investigating the genes involved in a specific developmental pathway in fruit flies (Drosophila). They discover a mutation in a gene resulting in the failure of proper segment formation during embryogenesis. What type of gene is most likely affected by this mutation?

During a research project, researchers discover a novel, small non-coding RNA molecule that appears to regulate gene expression. When this RNA is introduced into cells, it binds to a specific mRNA and causes the mRNA to be cleaved and degraded. What class of small non-coding RNA does the molecule belong to?

A researcher is studying a gene and finds that the gene's transcription rate rapidly decreases after the initial burst of expression, even though the necessary transcription factors remain present. What is the most likely mechanism responsible for this phenomenon?