A2 Genetic Control of Proteins and Control of Gene Expression Practice Test

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• Which statement best describes a transcriptional coactivator?
• Why would mixing blood from a boy with Factor IX deficiency with a haemophiliac who has Factor VIII deficiency clot?
• Name the organelle involved in translation.
• What type of molecule do homeobox genes encode?
• What is the function of a transcription factor?
• Which components form the spliceosome?
• If one tRNA has anticodon AGC and another has UUC, which amino acids are they carrying?
• Which termination mechanism is used by prokaryotes?
• What is the effect of histone acetylation on chromatin and transcription?
• How does a core promoter differ from a promoter?
• Define vector and expression vector.
• Which statement describes an event in translation?
• A tRNA molecule has anticodon UAA. Which amino acid does it carry?
• Explain the change in RNA concentration between 60% and 80% of the time spent as a pupa.
• What is a transcriptional repressor?
• DNA methylation and gene expression: which statement is correct?
• Which components participate in determining the order of amino acids during translation?
• Mutation could lead to a faulty Factor VIII protein by which mechanism?
• Which enzyme is directly responsible for adding nucleotides during DNA replication?
• What is a transcriptional corepressor?
• If the coding DNA sequence is ACT, what is the corresponding mRNA codon?
• What is alternative splicing and how can it affect protein output?
• What happens when a corepressor binds to the repressor in a repressible operon?
• What happens to transcription when an inducible operon is exposed to its inducer?
• Which regulatory mechanism increases lac operon transcription when glucose is scarce?
• Compare a promoter and an enhancer in terms of location and function.
• How is gene expression coordinated during development?
• Which technique is widely used for identifying and quantifying proteins based on mass-to-charge ratios?
• Which feature distinguishes tRNA from mRNA?
• What is the effect of a mutation that changes a codon to a stop codon?
• Where does translation occur in a cell?
• What happens to CAP activation when glucose is abundant?
• Which protein recognizes the TATA box to position RNA polymerase II for transcription initiation?
• AU-rich elements in mRNA influence stability by promoting what?
• If an mRNA segment contains five distinct codons, how many different tRNA molecules would be required to translate it?
• In studying operons, how do inducible and repressible operons differ, with examples?
• Which technique is widely used to quantify a specific protein using antibodies in solution?
• Which type of RNA is commonly involved in the splicing process?
• The researchers’ conclusions about flagella regrowth include actinomycin and puromycin experiments. Which statement best matches the evidence?
• Provide an example of how gene regulation influencing phenotype in a simple model organism.
• What is the outcome of alternative splicing?
• What is RISC and what is its role in RNAi?
• Which codon does the anticodon AGC pair with?
• In the mRNA sequence provided, what is the DNA sequence complementary to the first four bases in this section?
• Which statement best explains the roles of hydrolysis and condensation in protein formation?
• Why might a gene be under multiple layers of regulation (transcriptional, post-transcriptional, translational)?
• What is histone acetylation and how does it affect transcription?
• Which statement best describes transcriptional vs translational regulation?
• A protein is encoded by a piece of mRNA 660 nucleotides long. What is the maximum number of amino acids in the protein?
• What is the role of the promoter in transcription initiation?
• During translation, which statement correctly describes the bond that links amino acids to form the growing protein?
• A reporter gene assay uses a regulatory sequence to drive expression of a detectable gene; which of the following is commonly used as a reporter gene?
• Which statement about post-translational modifications in prokaryotes versus eukaryotes is true?
• What is a transcriptional activator?
• Which molecule carries amino acids to the ribosome during translation?
• What is a promoter-proximal element and why are they important?
• Which RNA polymerase transcribes tRNA?
• What is the function of the spliceosome?
• What is the primary function of promoter regions?
• What best describes the role of tRNA during translation?
• What is the role of the TATA box?
• Explain the concept of tissue-specific gene expression and its regulation.
• What does degeneracy of the genetic code mean?
• Which technique measures the expression levels of thousands of genes simultaneously?
• Which molecule directly carries amino acids during translation?
• Lysozyme is an enzyme formed from 129 amino acids. What is the minimum number of nucleotide bases required to code for this enzyme?
• Why are post-translational modifications necessary for many secreted proteins?
• A gene is 562 base pairs long but the corresponding mRNA is 441 nucleotides long. Explain the difference.
• Which of the following is classified as a long noncoding RNA?
• What is a common mechanism by which a transcriptional repressor inhibits transcription?
• Which statement accurately contrasts inducible and repressible operons with examples?
• What is RNA interference (RNAi) and how do siRNA and miRNA lead to gene silencing?
• During translation, which pairing occurs between tRNA and mRNA?
• How do microRNAs regulate gene expression?
• Explain why a base deletion mutation is often more disruptive than a base substitution.
• Which molecule serves as the template for mRNA synthesis during transcription in a typical eukaryotic cell?
• If the second mutation changes valine to alanine in the polypeptide, what could be the effect?
• What is an operator in prokaryotic operons?
• How many nucleotides code for one amino acid (the length of a codon)?
• The poly-A tail in mRNA primarily affects which aspects?
• Inducible expression requires what to turn on or off?
• Explain the change in RNA concentration in the first 40% of the time spent as a pupa.
• What is the tRNA anticodon for tyrosine?
• In which stage of the cell cycle do copying errors in DNA bases occur?
• What is the site where RNA polymerase initiates transcription called?
• Which technique is commonly used to determine the localization of a protein within tissue sections?
• How does chromatin remodeling influence gene expression?
• Which feature allows an expression vector to be replicated in host cells?
• What is an enhancer and how does it influence transcription?
• How can chromatin marks be inherited during cell division?
• Which component catalyzes peptide bond formation during translation?
• What is a selectable marker and why is it important in plasmid vectors?
• Which nucleotide is replaced by uracil in RNA?
• What is mRNA capping and polyadenylation and why are these modifications important?
• Which statement about glycosylation in expression systems is true?
• In a reporter gene assay, which element is typically placed upstream of the reporter gene to study regulation?
• Where does translation occur in a eukaryotic cell?
• Describe how ribosome initiation factors influence translation initiation.
• What term describes a DNA sequence with repeating bases that can lead to replication errors during copying?
• If the mRNA codon is UAU, which amino acid is encoded?
• How can recombinant DNA technology achieve expression of a human protein in bacteria?
• What type of molecule is encoded by homeobox genes?
• How does DNA methylation influence gene expression?
• If a deletion occurs in a coding region, what type of mutation is most likely to result?
• Which of the following is a post-translational modification?
• Which statement describes the Shine-Dalgarno sequence and its role?
• What is the role of lysosomes in metamorphosis?
• Which statement about enhancers is true?
• Tamoxifen is used to treat certain breast tumours. In the liver, tamoxifen is converted into an active substance called endoxifen. How does endoxifen reduce the growth of these tumours?
• In an expression plasmid, what is the primary role of the origin of replication?
• Why does estrogen affect only certain cells rather than all cells in the body?
• How does chromatin structure impact transcription initiation?
• What is attenuation in the trp operon and how does it control gene expression?
• Describe and explain how the altered gene could result in flax plants with white-coloured flowers.
• After transcription, mature mRNA is transported to the cytoplasm. Which option correctly states this process?
• What is meant by an allele?
• What is a transcriptional coactivator?
• Which statement best describes how eukaryotic transcription factors differ from prokaryotic regulators?
• Which features must an expression vector have?
• In the absence of lactose, what happens to lac operon transcription?
• What is a promoter-proximal element and why are they important?
• What is the role of alternative promoters?
• Distinguish constitutive expression from inducible expression.
• Tetracycline stops protein synthesis in bacteria. Which statement correctly describes its mechanism?
• Which statement accurately describes RNA polymerase II's transcription products?
• Explain RNA interference (RNAi) mechanism.
• How does transcription termination differ in prokaryotes vs eukaryotes?
• What is epigenetics?
• The length of the DNA coding region that codes for the toxin is longer than the mRNA used for translation. Explain why.
• Which statement best describes the 5' cap and 3' poly(A) tail on mRNA?
• Frameshift mutations near the start of a gene typically cause what kind of effect on the resulting protein?
• What is the effect of a repressor binding to the operator in a gene regulatory region?
• What is the function of a transcription factor when activated by a hormone?
• Which statement best describes a transcriptional activator's function when bound to DNA?
• Which molecule carries genetic information from the DNA to the ribosome for protein synthesis?
• Which of the following is an example of a non-coding RNA?
• Where do many eukaryotic transcription factors bind to regulate gene expression?
• How could an inserted gene reduce production of a softening enzyme?
• What is alternative splicing?
• Why can different adult proteins be produced from calliphorin in a fly larva?
• What is the role of tRNA in translation?
• What is the role of RNA polymerase in gene expression?
• What is the purpose of chromatin remodeling in gene regulation?
• Why do prokaryotes use operons while eukaryotes regulate genes with promoters, enhancers, and silencers?
• During translation, what is the role of tRNA?
• Which of the following would NOT be considered a mutagen or factor increasing mutation frequency?
• RNA polymerase synthesizes RNA in which direction?
• A protein contains 900 amino acids. What is the minimum number of nucleotides in the coding region of the mRNA that would encode this protein?
• Oestrogen is a hormone that affects transcription. It forms a complex with a receptor in the cytoplasm of target cells. How does an activated oestrogen receptor influence transcription in the target cell?
• What is a miRNA and its role?
• What is a chaperone protein and what is its role in protein folding?
• A piece of mRNA is 660 nucleotides long while the DNA coding strand from which it was transcribed is 870 nucleotides long. Why is the mRNA shorter?
• During processing of pre-mRNA to mature mRNA, which changes occur?
• RNA interference mechanism uses which molecules to guide RISC to target mRNA?
• Explain the role of epigenetic inheritance in gene expression.
• How do transcription factors interact with RNA polymerase II during initiation?
• Which statement about the genetic code is true?
• Why is promoter strength important in selecting a vector for gene expression?
• What are introns?
• What is the role of transcription factors in transcriptional regulation?
• What is a promoter and what is its role in transcription initiation?
• How does inhibiting acetylcholinesterase at neuromuscular junctions prevent breathing in the described toxin?
• Chlamydomonas uses its flagella to swim toward light of moderate intensity but away from very bright light. What is the advantage of this behavior?
• What is splicing and what is the consequence of alternative splicing?
• During DNA replication, which statement is correct?
• Which statement best describes the difference between general transcription factors and locus-specific transcription factors?
• What statement best describes the role of transcription factors in eukaryotic transcription?
• What are nucleosomes and why is chromatin structure important for gene expression?
• What is the function of a transcriptional repressor?
• Two differences between the structures of mRNA and tRNA.
• What are the components of a bacterial operon and why is it significant?
• Nonsense-mediated decay (NMD) primarily serves to degrade transcripts that contain what feature?
• In eukaryotic cells, an expression vector typically contains what to drive gene expression?
• If a mutation prevents RNA polymerase from binding to the promoter, what is the most likely outcome for transcription?
• What are post-translational modifications and why are they essential for protein function?
• What is a plasmid expression vector and what key elements does it typically contain?
• Which molecule inhibits the lac operon repressor when lactose is present, allowing transcription?
• Which statement best describes inducible expression systems?
• What is codon optimization and why is it used in heterologous protein expression?
• If a mutation changes a codon but still codes for the same amino acid, what is the effect on the resulting polypeptide?
• Which statement best describes Tet-On/Tet-Off inducible systems?
• How do signal transduction pathways influence gene expression?
• How do enhancers communicate with promoters if they are located far away?
• Post-translational modifications can affect which aspects of a protein?
• How does mRNA stability influence gene expression?
• What is the primary purpose of a reporter gene assay?
• How can mutations in promoter regions affect gene expression?
• What is a uORF (upstream open reading frame) and how does it regulate translation?
• Which event occurs during translation?
• The 5' UTR can influence translation by what mechanism?
• What is a plasmid?
• Starting with mRNA in the nucleus, which sequence best describes how translation produces a polypeptide?
• Which technique is commonly used to measure gene expression levels at the mRNA level with real-time quantification?
• Name one mutagenic agent.
• If enhancers are located far from promoters, which mechanism allows them to regulate transcription?
• How do regulatory sequence mutations influence phenotype?
• What is the role of initiation factors in eukaryotic translation initiation?
• What is a signal peptide and why is it important for protein targeting?
• Which statement distinguishes pre-mRNA from mature mRNA?
• How does the ubiquitin-proteasome system regulate protein levels?
• If a base is copied more than once during DNA replication, what effect may this have on the resulting protein?
• Which statement best describes transcription?
• Which example is a chemical mutagen?
• What is a promoter-proximal element?
• Which molecule contains an amino acid binding site?
• If the mRNA codon for threonine is ACC, what is the complementary DNA template strand sequence?
• Why is codon optimization used in expressing human proteins in bacteria?
• Which element is part of the core promoter and essential for transcription initiation?
• The genetic code is degenerate, meaning?
• Which statement best describes the difference between transcriptional regulation and translational regulation?
• What is a transcription factor and what is its general role?
• What is the core promoter minimal sequence concept?
• How would the number of lysosomes in a pupa be expected to change with age? Give a reason.
• How does glucose availability influence lac operon expression via cAMP and CRP?
• Which description correctly explains how a change in the DNA base sequence can affect the protein's three-dimensional structure?
• How does the concentration of RNA change during the time spent as a pupa?
• Why might a deletion mutation have a greater effect than a base substitution?
• What is a spliceosome and what role does it play in gene expression?
• What is the role of RNA polymerase in transcription?
• Which statement best describes DNA methylation in gene regulation?
• Which statement best describes the lac operon and its regulation in bacteria?
• Describe how a deletion mutation alters the structure of a gene.
• What is a silencer element?
• How does tissue-specific gene expression contribute to organ function?
• How could a change in the base sequence of the mRNA lead to a change in the tertiary structure of the toxin?
• The mRNA codon for the amino acid tyrosine is UAU. What is the corresponding DNA triplet for tyrosine?
• What is the role of homeobox genes in development?
• In an inducible operon, what is the role of the inducer?
• What is the primary difference between RNA editing and alternative splicing?
• What is the general role of a transcription factor?
• What type of bonds form between nucleotides during transcription?
• Define an enhancer and its role in eukaryotic transcription.
• Which molecule acts as the inducer for the lac operon by inactivating the lac repressor?
• Which statement correctly describes how lactose regulation of lac operon works in the presence of lactose?
• What is a silent allele and how can gene expression be silenced in eukaryotes?
• What explains differences in base composition between two regions of a chromosome?
• How can enhancers regulate gene expression from a distance?
• How can CRISPR be used to control gene expression?
• In eukaryotic translation initiation, the ribosome begins scanning from which feature toward the start codon?
• Which RNA polymerase transcribes rRNA in eukaryotes?