Title: Gene Expressions
Course: Question Banks

Q: Gene expression is ________.
- simply transcription (Incorrect. Gene expression is not only transcription.)
- only translation (Incorrect. Gene expression is not only translation)
- both transcription and translation (Correct. Expression of a gene involves transcription of DNA into RNA followed by translation to a functional protein.)
A: both transcription and translation

Q: ________ is required to give cells unique specializations.
- Protein synthesis (Incorrect. Protein synthesis alone would be make cells unique.)
- DNA replication (Incorrect. DNA replication should be the same in all cells of a multicellular organism.)
- Gene expression (Correct. Without difference in gene expression, cells could have not unique functions in an organism.)
A: Gene expression

Q: Cells express different genes in response to ________.
- internal triggers (Incorrect. Cells do not express different genes only in response to internal triggers.)
- external signals (Incorrect. Cells do not express different genes only in response to external triggers.)
- internal triggers and external signals (Correct. Internal and external signals can both result in different gene expression patterns in cells.)
A: internal triggers and external signals

Q: In ________, transcription and translation occur simultaneously.
- eukaryotes (Incorrect. In eukaryotes transcription and translation occur in two very different cellular locations.)
- both prokaryotes and eukaryotes (Incorrect. In eukaryotes transcription and translation occur in two very different cellular locations.)
- prokaryotes (Correct. Because DNA is not sequestered in a nucleus away from translation machinery like ribosomes, transcription and translation occur almost simultaneously in prokaryotes.)
A: prokaryotes

Q: Prokaryotic gene regulation occurs at the level of ________.
- translation (Incorrect. Gene regulation is not at the level of translation in prokaryotes.)
- both transcription and translation (Incorrect. Gene regulation is not at the level of translation in prokaryotes.)
- transcription (Correct. Gene regulation in prokaryotes occurs by regulating which DNA is transcribed.)
A: transcription

Q: ________ gene regulation occurs from transcription beyond translation.
- Prokaryotic (Incorrect. Gene regulation in prokaryotes occurs by regulating which DNA is transcribed.)
- Both eukaryotic and prokaryotic (Incorrect. Gene regulation in prokaryotes occurs by regulating which DNA is transcribed.)
- Eukaryotic (Correct. Gene regulation in eukaryotes occurs from DNA transcription through post-translational modification of proteins.)
A: Eukaryotic

Q: In prokaryotes, structural proteins in a single biochemical pathway are usually found as a(n) ________ within the genome.
- cluster (Incorrect. The proteins are often encoded together within the genome but we don’t call them a cluster.)
- polycistronic transcript (Incorrect. This is the term for the mass transcription of proteins with related functions.)
- operon (Correct. Proteins with related functions are usually encoded together in a block called an operon.)
A: operon

Q: Gene products that are needed consistently are ________ in prokaryotes.
- always on (Incorrect. While arguably true, this isn’t the terminology we use.)
- activated (Incorrect. Activation refers to the increased transcription of a gene in response to a specific external stimulus.)
- constitutively expressed (Correct. These genes are transcribed and translated continuously to provide the cell with constant levels of the protein products.)
A: constitutively expressed

Q: In prokaryotes the ________ is located between the RNA polymerase binding site and the transcriptional start of the first gene in an operon.
- repressor (Incorrect. A repressor is a transcription factor that suppresses transcription in response to an external stimulus.)
- inducer (Incorrect. An inducer is a regulatory molecule that may activate or repress transcription.)
- operator (Correct. The operator is a regulatory region between the RNA polymerase binding site and the start of transcription that a repressor or inducer may bind.)
A: operator

Q: Changes in gene regulation that are caused by modifications to histones and the DNA, but not the nucleotide sequence itself, are known as ________.
- hypermethylation (Incorrect. Hypermethylation is an example of this type of regulation.)
- CpG islands (Incorrect. CpG islands often experience this type of gene regulation.)
- epigenetic (Correct. These regulations “around genetic” sequences are temporary and do not directly alter the nucleotide sequence.)
A: epigenetic

Q: The key to epigenetic regulation is ________.
- physical modification of the DNA (Incorrect. There is no physical modification of the actual DNA strand.)
- biochemical modification of binding factors (Incorrect. Binding factors are not modified in any way by epigenetic modifications.)
- controlling accessibility to transcription factors and RNA polymerase binding (Correct. Epigenetic changes influence whether the DNA strand is open to expose the template.)
A: controlling accessibility to transcription factors and RNA polymerase binding

Q: Tightly coiled DNA is ________.
- known as hypermethylated (Incorrect. Hypermethylation is one factor that influences how tightly DNA is coiled.)
- translationally regulated (Incorrect. Tight coiling of DNA does not regulate translation.)
- transcriptionally inactive (Correct. Tightly coiled DNA cannot be accessed by transcription machinery.)
A: transcriptionally inactive

Q: For transcription to begin in eukaryotes, ________ must bind the DNA first.
- RNA polymerase (Incorrect. In eukaryotes, RNA polymerase is not the first thing that binds to the DNA molecule.)
- enhancers (Incorrect. Enhancers are regions of DNA that help increase transcription.)
- transcription factors (Correct. Transcription factors must bind to the promoter region first and then recruit RNA polymerase to begin transcription.)
A: transcription factors

Q: ________ brings an enhancer into contact with transcription factors and other proteins to increase transcription.
- Mediator protein (Incorrect. Mediator proteins are one of the other proteins that enhancers interact with to increase transcription.)
- RNA polymerase plus (Incorrect. There is no RNA polymerase plus.)
- DNA-bending protein (Correct. This protein brings the enhancer into physical proximity with transcription factors and mediator proteins.)
A: DNA-bending protein

Q: A(n) ________ prevents the binding of transcription factors.
- inhibitor (Incorrect. Inhibitors do not prevent the binding of transcription factors.)
- enhancer (Incorrect. Enhancers do not prevent the binding of transcription factors.)
- repressor (Correct. A repressor prevents a gene from being transcribed.)
A: repressor

Q: RNA splicing occurs in the ________.
- nuclear membrane (Incorrect. No RNA modifications occur in the nuclear membrane.)
- cytoplasm (Incorrect. Only mature mRNA is found in the cytoplasm.)
- nucleus (Correct. Pre-mRNA is spliced into mRNA before the transcript leaves the nucleus.)
A: nucleus

Q: RNA splicing removes ________ from the RNA transcript.
- axons (Incorrect. Axons are parts of neurons.)
- exons (Incorrect. Exons are the regions of RNA that code for proteins.)
- introns (Correct. Introns must be removed from the transcript before mature mRNA can be translated.)
A: introns

Q: Alternative splicing allows ________.
- the same mRNA sequence to be created from different DNA templates (Incorrect. Different DNA templates cannot be used to generate the same mRNA.)
- some introns to be left in coding regions to protect the mRNA (Incorrect. Introns do not protect the mRNA.)
- different protein products to be produced from one gene (Correct. Alternative splicing stitches together different combinations of exons from the same pre-mRNA. This allows for a single gene to encode for multiple protein products.)
A: different protein products to be produced from one gene

Q: The rate at which RNA decays is known as ________.
- half-life (Incorrect. Half-life indicates the rate at which radioactive isotopes decay.)
- RNA longevity (Incorrect. This is not the correct term.)
- RNA stability (Correct. RNA stability is the rate at which an RNA molecule decays once in the cytoplasm.)
A: RNA stability

Q: ________ play a role in destroying mRNA targets.
- siRNAs (Incorrect. Short-interfering RNAs can trigger mRNA degradation but this is not a normal regulatory process.)
- RBPs (Incorrect. Some RNA-binding proteins play a role in stabilizing mRNA targets; they do not all play a role in degradation.)
- miRNAs (Correct. microRNAs bind to an mRNA target along with RISC to degrade that molecule.)
A: miRNAs