Molecular Genetics Practice Exam

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• What term describes the pairing of complementary DNA strands to form the double helix?
• In DNA replication, which strand is synthesized discontinuously in short segments?
• Which statement about frameshift mutations is correct?
• How does RFLP-based DNA fingerprinting differentiate individuals?
• Which protein binds to the operator in the lac operon to prevent transcription?
• Which type of mutation results in no change to the amino acid sequence?
• During DNA replication, what are the fragments called on the lagging strand?
• What is alternative splicing and how does it contribute to proteome diversity? Provide FGFR2 example.
• What is the effect of histone acetylation on chromatin and transcription?
• Define PCR; describe the three main steps and the importance of primer design and melting temperature considerations.
• Which mutation describes a change of a single amino acid in a protein?
• Which statement best describes the relationship between mismatch repair and microsatellite instability and cancer predisposition?
• DNA's shape is described as a double what?
• How do restriction enzymes and DNA ligase enable recombinant DNA technology; outline a typical cloning workflow.
• In bisulfite sequencing, what does single-base resolution mean?
• Which statement correctly distinguishes prokaryotic cells from eukaryotic cells?
• Which molecule carries amino acids during translation?
• What enzyme synthesizes the RNA primers required for DNA synthesis?
• Why are reference genes used in RT-qPCR experiments?
• What describes a type of mutation that changes a single nucleotide?
• Which RNA forms the structural and catalytic core of ribosomes?
• Which statement about eukaryotic mRNA processing is true?
• Single ringed nitrogenous base.
• Which statement best describes a plasmid backbone and factors influencing its stability in bacterial expression systems?
• Which organelle is typically absent in prokaryotic cells but abundant in eukaryotes?
• Which statement is true about prokaryotic cells?
• Which statement correctly describes bisulfite sequencing and how it detects DNA methylation?
• Which statement correctly defines epigenetics and describes the roles of DNA methylation and histone acetylation in gene expression?
• Which feature of a cDNA library makes it suitable for expression profiling?
• Which statement accurately describes DNA structure and Chargaff's rules?
• What are the short DNA fragments formed on the lagging strand during DNA replication?
• What defines an operon, and how does lac operon regulation illustrate positive and negative control?
• Which experimental design best tests whether a regulatory element drives tissue-specific expression using a reporter assay?
• Which enzyme seals the backbone after DNA fragments are synthesized?
• Describe recombination frequency and how it is used to map genes; define cis vs trans configurations.
• The start codon codes for which amino acid?
• What is the difference between a promoter, enhancer, and insulator, and how do chromatin boundaries affect gene regulation?
• Which term describes a molecule that consists of sugar, phosphate, and nitrogenous base?
• In a Western blot, what is typically used to detect the target protein?
• The two strands of DNA intertwine to form a structure called the?
• In the trp operon, what molecule acts as the corepressor by binding to the repressor?
• Which statement best contrasts transcription initiation in prokaryotes and eukaryotes?
• Which product is commonly produced using recombinant DNA technology in biotechnology?
• Why do mitochondrial diseases show variable penetrance among individuals?
• Which nitrogenous base is found only in RNA?
• Which genetic element is a small circular DNA molecule in bacteria capable of transfer between cells and often carrying antibiotic resistance genes?
• What advances overcome Sanger's throughput limitations?
• Which statement best contrasts Northern blot quantification with RT-qPCR for measuring RNA abundance?
• Which technique analyzes DNA fragment lengths after restriction enzyme digestion?
• What term refers to the repetitive DNA at chromosome ends that protect genetic information during cell division?
• Which technique separates DNA fragments by size using electrical charges?
• Which process produces a protein from an mRNA template?
• Describe base excision repair as it corrects a cytosine deaminated to uracil, including the roles of the key enzymes.
• In an operon, which element mediates negative regulation by a repressor?
• Which term describes using living organisms to produce useful products?
• What is a haplotype?
• What are base editing and prime editing, and how do they differ from classic CRISPR-Cas9 knockout strategies?
• Which statement best describes dosage compensation mechanisms in mammals and Drosophila?
• Which statement is true about blotting techniques Southern, Northern, and Western?
• Unzips DNA.
• What type of bonds link atoms in the DNA backbone?
• Which statement best describes how epigenetic marks influence X chromosome inactivation and imprinting?
• The backbone of DNA is composed of which components?
• Which molecule serves as the corepressor in the lac operon by binding to the repressor?
• Type of tail that protects mRNA?
• Which enzyme is responsible for laying down RNA primers during DNA replication?
• Type of sugar in RNA?
• Describe CRISPR gene drives and discuss potential risks, resistance mechanisms, and containment strategies.
• Monomer of a polypeptide.
• What carries the genetic message from DNA to the ribosome?
• DNA is which type of molecule?
• Which segment of DNA codes for proteins?
• Explain the design considerations for siRNA and shRNA for effective gene knockdown in mammalian cells, including off-target concerns.
• What is the role of the PAM sequence in CRISPR-Cas9 targeting?
• In synthetic biology, which description best characterizes a toggle switch?
• What is the small circular DNA molecule in bacteria that can be transferred between cells?
• Which makes polypeptides?
• How many hydrogen bonds form between adenine and thymine in DNA?
• Single-stranded version of a gene; recipe for a protein.
• What are the central dogma exceptions involving reverse transcription and RNA genome replication?
• Which enzyme adds nucleotides during DNA replication?
• What is linkage disequilibrium and how is it used in mapping disease genes?
• What technique is used to amplify DNA by repeated cycles of heating and cooling?
• Which statement best describes a repressilator, a synthetic biology oscillator?
• Which molecular complex removes introns from pre-mRNA?
• Which term refers to a stable change in the genetic material that can be inherited?
• Which mutation type involves a segment of DNA being reversed in orientation within the chromosome?
• What are the general steps of RNA interference, and how do siRNA and miRNA differ in their mechanisms?
• Which component forms the backbone of both DNA and RNA?
• What type of bonds connect the nitrogenous bases in DNA?
• What best describes prime editing in comparison to standard CRISPR-Cas9 knockout?
• Which mutation type replaces one amino acid with another?
• What is used to cut DNA into fragments for analysis or cloning?
• Which genetic element in bacteria is commonly used to carry antibiotic resistance genes?
• Imprinting involves parent-specific DNA methylation patterns established during gametogenesis and maintained after fertilization to silence either the paternal or maternal allele. Which statement is true?
• Which DNA strand is used as the template for RNA synthesis in transcription?
• What term describes a cell that has no nucleus?
• Which mutation arises from adding or deleting one or two bases, shifting the reading frame?
• What term describes a double-ring nitrogenous base?
• Which term best describes a single unit of DNA or RNA that includes sugar, phosphate, and base?
• Which type of mutation introduces a premature stop codon?
• Which of the following is a classic example of biotechnology?
• What term describes repetition or redundancy in the genetic code?
• A group of three nucleotides on mRNA that codes for a specific amino acid.
• In attenuation control of the bacterial trp operon, what happens when tryptophan is abundant?
• Why is Sanger sequencing limited for high-throughput sequencing?
• Which base type has a single ring in nucleic acids?
• In mammals, which RNA is essential for initiating X-chromosome inactivation?
• How are collapsed replication forks typically repaired?
• Explain the role of telomerase in chromosome end maintenance and why telomere shortening limits somatic cell division.
• What is a key advantage of RNA-Seq over microarrays for expression profiling?
• Can be used to analyze DNA by transferring to a nylon membrane and probing for fragments?
• Differentiate between a silent, missense, nonsense, and frameshift mutation; provide an example of each and their likely phenotypic effect.
• What is the sequence of the start codon?
• Which protein complex is responsible for upregulating the X chromosome in male Drosophila?
• Describe how CRISPR-Cas9 works, including the role of PAM and guide RNA, and how off-target effects are addressed.
• Which statement best captures Chargaff's rules for double-stranded DNA?
• Which term describes the process of pairing complementary strands to form a double-stranded DNA molecule, often during primer annealing?
• Uracil in RNA replaces which base in DNA?
• Which term best describes a hereditary change in the DNA sequence that can be passed to offspring?
• Which base is unique to DNA and not typically found in RNA?
• Which mutation type involves a DNA segment moving from one location to another within the genome?
• What is the difference between genotype and phenotype, and what does pleiotropy mean?
• In lac operon regulation, which molecule binds the LacI repressor to relieve repression?
• In Hardy-Weinberg equilibrium, genotype frequencies in a large, random-mating population with no selection are p^2, 2pq, and q^2. Which option BEST expresses this principle?
• In plasmid vector design, which factor primarily determines plasmid copy number?
• Which of the following is an example of a mutation type?
• Which codon is universally recognized as the start codon in bacteria?
• Which mutation involves the two DNA strands flipping positions, or turning around?
• What term refers to the region found at the center of a chromosome where the sister chromatids are held together?
• During replication stress, what happens when replication forks stall?
• Which enzyme is responsible for unwinding the DNA helix during replication?
• What is the process called when bacteria transfer plasmids to another cell?
• In the tryptophan operon, which molecule serves as the corepressor by binding to the repressor?
• In DNA, the sugar component of the backbone is which sugar?
• Which statement best describes mutational hotspots in DNA?
• Which statement correctly contrasts nucleotide excision repair (NER) and mismatch repair (MMR) in terms of lesions repaired and consequences when defective?
• What is promoter-proximal pausing and what is required for the transition into productive elongation?
• Define GWAS and the concept of polygenic risk scores; discuss limitations and population stratification concerns.
• Which enzyme relieves torsional strain ahead of the replication fork by introducing negative supercoils?
• Which term best describes the polymeric subunits of DNA and RNA?
• Which field encompasses the use of living systems to create commercially valuable products?
• Describe the mechanism of DNA replication on the leading and lagging strands, including the roles of DNA polymerase, primase, ligase, and Okazaki fragments.
• DNA's charge?
• Which DNA strand is used as the template to produce mRNA?
• 5' cap protecting mRNA is which molecule?
• DNA subunit is called what?
• What is the function of XIST in X-chromosome inactivation?
• Which model describes DNA replication where each new double helix consists of one original strand and one newly synthesized strand?
• Which molecule transfers amino acids during translation?
• Which processes enable cells to bypass stalled replication forks?
• Which type of cell allows transcription and translation to occur in the same compartment?
• What is a change in DNA sequence caused by radiation or chemicals?
• Type of sugar in DNA?
• Which mutation moves a section of DNA to a new location within the genome?
• Explain the role of riboswitches in prokaryotes; how do metabolite binding events influence transcription or translation?
• How does STR analysis differentiate individuals?
• Which strand is synthesized continuously during DNA replication?
• Which type of mutation would most likely have a drastic effect on protein function when it occurs in a coding region?
• What is the basic principle of Sanger sequencing?
• Which molecule stores genetic information in most organisms?
• What is the name of the process by which mRNA is synthesized from a DNA template?
• How do enhancers and silencers differ from promoter proximal elements, and how do chromatin structure and histone modifications influence access?
• In plasmid design, which factor mainly controls expression strength?
• Which process creates many copies of a DNA segment?
• Adds new DNA nucleotides to a replicating DNA molecule.
• Which statement best explains heteroplasmy in mitochondrial inheritance?
• Which library type originates from mRNA and reflects expressed genes?
• Protects the ends of the chromosomes; when they degrade, the cell dies.
• Which molecule makes up the ribosome?
• What is a common mechanism by which populations may resist a gene drive?
• What genetic element do bacteria carry that can encode antibiotic resistance and replicate independently?
• Which statement describes a major ethical or ecological concern associated with releasing gene drives into wild populations?
• What is the effect of histone acetylation by histone acetyltransferases (HATs) on chromatin structure and transcription?
• Group of three bases found on tRNA that pairs with codons.
• How do microarrays measure gene expression?
• In DNA structure, the two strands run in opposite directions, a property known as what?
• Direction that new DNA is built in during replication?
• Describe the role of DNA polymerases during replication in eukaryotes: Pol alpha, delta, and epsilon functions.
• Which description best defines biotechnology?