DNA Gyrase and DNA Polymerases Quiz
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Questions and Answers

What was the major criteria for a molecule to serve as genetic material?

  • Replicate, translate information, express information, allow variation by mutation
  • Replicate, store information, express information, allow variation by mutation (correct)
  • Replicate, store energy, express information, allow variation by recombination
  • Replicate, store information, transcribe information, allow variation by mutation

    • Who provided the first direct experimental proof that DNA is the biomolecule responsible for heredity?

  • Avery, MacLeod, and McCarty (correct)
  • Griffith
  • Streptococcus pneumoniae
  • Phagocytes

    • What did Griffith's Transformation Experiment demonstrate?

  • Dead encapsulated bacteria could be transformed to avirulence
  • Living encapsulated bacteria could be transformed to virulence (correct)
  • Living nonencapsulated bacteria could be transformed to virulence
  • Dead nonencapsulated bacteria could be transformed to avirulence

    • What did Griffith's experiment with Streptococcus pneumoniae suggest about the transforming principle?

    <p>It could be part of polysaccharide capsule or compound required for capsule synthesis</p> Signup and view all the answers

    What is the function of telomerase?

    <p>To prevent loss of integrity of the linear DNA strand</p> Signup and view all the answers

    What is the role of telomerase in cancer cells?

    <p>Activation of telomerase to maintain telomere length</p> Signup and view all the answers

    What is the primary function of reverse transcriptase?

    <p>To read RNA and make DNA</p> Signup and view all the answers

    How do nucleoside analogs inhibit chain growth of DNA transcribed by reverse transcriptase?

    <p>By competing with naturally occurring nucleotides for incorporation into the viral DNA strand</p> Signup and view all the answers

    What is the function of mRNA in protein synthesis?

    <p>To serve as a blueprint for generating proteins in the ribosome</p> Signup and view all the answers

    What is unique about the 5' end of mRNA in eukaryotes?

    <p>It contains a cap structure with a methylated Guanine Triphosphate</p> Signup and view all the answers

    What is the role of rRNA in protein synthesis?

    <p>It forms the ribosome subunits and has ribozyme activity in protein synthesis</p> Signup and view all the answers

    What is the primary function of tRNA?

    <p>Carrying amino acids to the ribosome for protein synthesis activity</p> Signup and view all the answers

    Which enzyme is responsible for synthesizing a new RNA chain from DNA?

    <p>RNA Polymerase</p> Signup and view all the answers

    What are the precursors for RNA chain synthesis?

    <p>rNTP's (ribose nucleosides triphosphates)</p> Signup and view all the answers

    What are the core subunits of prokaryotic RNA Polymerase?

    <p>alpha2/beta/beta' and a fifth unit called sigma factor</p> Signup and view all the answers

    Which enzyme catalyzes the formation of peptide bonds in protein translation?

    <p>Peptidyl Transferase</p> Signup and view all the answers

    What did Avery, MacLeod, and McCarty discover about the transforming principle?

    <p>It is DNA, not protein</p> Signup and view all the answers

    What did Hershey and Chase demonstrate about the genetic material?

    <p>DNA is the genetic material</p> Signup and view all the answers

    What is the composition of eukaryotic chromatin?

    <p>DNA complexed with histones</p> Signup and view all the answers

    What does mitochondrial DNA encode?

    <p>Specific protein subunits of the Electron Transport Chain, ribosomal RNA, and transfer RNA</p> Signup and view all the answers

    When does DNA replication occur?

    <p>During the S phase of cell replication</p> Signup and view all the answers

    What enzyme adds new nucleotides during DNA replication?

    <p>$DNA$ polymerase</p> Signup and view all the answers

    Which DNA polymerase is responsible for replicating mitochondrial DNA in eukaryotes?

    <p>DNA Polymerase γ</p> Signup and view all the answers

    What is the main function of DNA ligase during DNA replication?

    <p>To join Okazaki fragments on the lagging strand</p> Signup and view all the answers

    Which type of topoisomerase is DNA Gyrase?

    <p>Type II Topoisomerase</p> Signup and view all the answers

    What is the function of RNase H during DNA replication?

    <p>To remove RNA primers</p> Signup and view all the answers

    Which enzyme is responsible for elongating Okazaki fragments on the leading strand?

    <p>DNA Polymerase δ</p> Signup and view all the answers

    What is the role of pol I in prokaryotic DNA replication?

    <p>Removes RNA primer and fills in gaps on the lagging strand.</p> Signup and view all the answers

    What is the function of pol II in prokaryotic DNA replication?

    <p>Involved in DNA replication and repair.</p> Signup and view all the answers

    What is the primary function of pol III in prokaryotic DNA replication?

    <p>The major replicative enzyme.</p> Signup and view all the answers

    Which enzyme catalyzes the covalent bond between a phosphate group on one nucleotide and the deoxyribose of the next nucleotide?

    <p>Polymerase</p> Signup and view all the answers

    What causes halting of DNA replication due to thymine dimers?

    <p>UV light exposure</p> Signup and view all the answers

    What happens when telomere DNA repeats are consumed?

    <p>The cell stops dividing.</p> Signup and view all the answers

    Which enzyme binds to specific promoter regions on DNA, marking gene locations?

    <p>Sigma factor</p> Signup and view all the answers

    What is the sequence found around 10 bases before the transcription start site in promoter regions?

    <p>TATAAT</p> Signup and view all the answers

    In which direction does RNA polymerase transcribe one strand at prokaryotic promoters?

    <p>3' to 5'</p> Signup and view all the answers

    In which direction does RNA grow during transcription?

    <p>5' to 3'</p> Signup and view all the answers

    What prevents supercoiling of DNA during transcription?

    <p>Topoisomerases</p> Signup and view all the answers

    Under what conditions does RNA molecule termination occur?

    <p>When it becomes tail heavy</p> Signup and view all the answers

    Which antibiotics inhibit bacterial RNA polymerase activity?

    <p>Rifampicin and quinolones</p> Signup and view all the answers

    Which type of RNA polymerase synthesizes mRNA in eukaryotes?

    <p>RNA polymerase II</p> Signup and view all the answers

    What is the role of a karyotype?

    <p>To provide an ordered display of an individual's chromosomes</p> Signup and view all the answers

    What are homologous chromosomes matched in?

    <p>Length, centromere position, and staining pattern</p> Signup and view all the answers

    Where is most DNA located in a cell?

    <p>In the nucleus on chromosomes</p> Signup and view all the answers

    What is the primary function of genes?

    <p>To determine biologically inherited traits</p> Signup and view all the answers

    Which type of inheritance pattern is associated with hereditary hemochromatosis?

    <p>X-linked inheritance</p> Signup and view all the answers

    What is the likelihood of an affected male transmitting the mutant gene to his daughters?

    <p>50%</p> Signup and view all the answers

    What is the ratio of males in the population affected by hemophilia A?

    <p>1:5,000</p> Signup and view all the answers

    What is the primary cause of hemophilia A?

    <p>Mutations or deletions in the Factor VIII gene (F8)</p> Signup and view all the answers

    What defines the severity of hemophilia A?

    <p>% of FVIII levels to normal levels</p> Signup and view all the answers

    What is the likelihood of a heterozygous woman transmitting the mutant gene to her sons?

    <p>50%</p> Signup and view all the answers

    What type of disorder is hemophilia A?

    <p>X chromosome-linked recessive coagulation disorder</p> Signup and view all the answers

    What can simulate autosomal dominant inheritance in small pedigrees for hemophilia A?

    <p>Mating between an affected male and a heterozygous female</p> Signup and view all the answers

    Which type of genetic disorder is Down syndrome?

    <p>Trisomic disorder</p> Signup and view all the answers

    What is the most common mechanism leading to Down syndrome?

    <p>Nondisjunction of chromosome 21 during meiosis</p> Signup and view all the answers

    Which diagnostic tests can detect chromosomal abnormalities in the fetus before birth?

    <p>Amniocentesis and chorionic villus sampling (CVS)</p> Signup and view all the answers

    What is the genetic condition characterized by an XXY genotype?

    <p>Klinefelter syndrome</p> Signup and view all the answers

    What type of genetic disorders result from the combined action of multiple genes?

    <p>Polygenic disorders</p> Signup and view all the answers

    What is the term for the loss of one chromosome in a pair?

    <p>Monosomy</p> Signup and view all the answers

    What can be detected through karyotyping?

    <p>Homologous chromosome pairs, chromosome number, and structure</p> Signup and view all the answers

    What can result from mutations at the level of individual genes?

    <p>Monosomy</p> Signup and view all the answers

    Study Notes

    • Sigma factor binds to specific promoter regions on DNA, marking gene locations

    • Promoter regions contain the TATAAT box around 10 bases before transcription start

    • RNA polymerase binds to prokaryotic promoters, transcribing one strand in the 3’ to 5’ direction

    • RNA grows in the 5’ to 3’ direction as RNA polymerase catalyzes phosphodiester bond formation

    • Supercoiling is avoided by topoisomerases

    • RNA molecule termination occurs when it becomes tail heavy or when Rho factor disrupts RNA-DNA association

    • Antibiotics like rifampicin and quinolones inhibit bacterial RNA polymerase and ligase activities

    • RNA polymerere I, II, and III synthesize rRNA, mRNA, and tRNA in eukaryotes, respectively

    • RNA Polymerase II requires transcription factors and complex formation to initiate mRNA synthesis

    • Initiation of mRNA synthesis involves RNA polymerase binding to the promoter, unwinding DNA, and separating bases

    • mRNA contains a 5’ cap and a 3’ polyadenylated tail for protection from degradation

    • mRNA undergoes posttranscriptional modification including removal of introns through splicing

    • Alternative splicing can result in multiple protein products from a single mRNA transcript

    • Gene expression can be regulated by controlling transcription initiation or through posttranscriptional mechanisms including small RNAs and mRNA degradation.

    • Karyotypes are produced from cells arrested at metaphase of mitosis, revealing homologous chromosome pairs and chromosome number and structure.

    • Chromosomal abnormalities can be detected through karyotyping, including modifications at the level of chromosomes and variations in chromosome number.

    • Phenotypic variations can result from mutations at the level of individual genes.

    • Chromosome aberrations include variations in chromosome number, such as monosomy (loss of one chromosome) and trisomy (gain of one chromosome), which can result in a range of phenotypic effects.

    • Monosomy (loss of one chromosome) can be lethal, while trisomy (gain of one chromosome) can be more viable, producing conditions like Down syndrome (trisomy 21).

    • Down syndrome is caused by an extra copy of chromosome 21 and is characterized by a specific set of symptoms, including developmental disabilities, heart defects, and susceptibility to certain diseases.

    • Nondisjunction of chromosome 21 during meiosis is the most common mechanism leading to Down syndrome.

    • Diagnostic testing, such as amniocentesis and chorionic villus sampling (CVS), can detect chromosomal abnormalities in the fetus before birth.

    • Nondisjunction of sex chromosomes can lead to various nonlethal genetic disorders, including Klinefelter syndrome (XXY genotype) and Turner syndrome (XO).

    • Human traits can be controlled by multiple genes, following genetics principles like Mendelian inheritance (autosomal dominant and recessive), pedigree analysis, and Punnett square.

    • Monogenic disorders are caused by mutations in a single gene, while polygenic disorders result from the combined action of multiple genes.

    • Environmental factors can interact with genetics to influence human traits and diseases.

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    Description

    Test your knowledge on DNA Gyrase, a Type II Topoisomerase used in prokaryotes, and the different types of DNA Polymerases in prokaryotes and eukaryotes. Learn about Ciprofloxacin's role in inactivating DNA Gyrase and the functions of various DNA Polymerases.

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