Molecular Diagnostics & Genetics Quiz
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Questions and Answers

What is the term for the variation in size of DNA fragments produced by restriction enzymes?

  • Haplotype
  • Genome sequencing
  • Intron variation
  • Polymorphism (correct)

    • Which of the following correctly defines a haplotype?

  • A repetitive DNA sequence at the chromosome end
  • A combination of different alleles at a locus
  • A series of alleles on a single chromosome (correct)
  • A cell with a single genome copy

    • What does the term 'transcription' refer to in genetic processes?

  • The variation of alleles at a genetic locus
  • The process of DNA replication
  • The joining of two DNA molecule ends
  • The copying of genetic information from DNA to mRNA (correct)

    • Which definition best describes 'haploid' cells?

    <p>Cells with one copy of the genome</p> Signup and view all the answers

    What is the primary function of telomeres in chromosomes?

    <p>To prevent chromosome degradation</p> Signup and view all the answers

    Which of the following correctly explains what STRs are?

    <p>Short sequences of DNA repeated numerous times</p> Signup and view all the answers

    What characterizes individuals with heterozygous alleles?

    <p>Having two different alleles at a locus</p> Signup and view all the answers

    Which process is described as the joining of two DNA molecule ends?

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

    What is the primary function of agarose in molecular diagnostics?

    <p>To form gels for separating DNA</p> Signup and view all the answers

    Which statement accurately describes the term 'penetrance' in genetics?

    <p>It measures the probability of expressing a phenotype given a genotype.</p> Signup and view all the answers

    How do epigenetic changes affect gene expression?

    <p>By regulating gene activity without changing the gene DNA sequence</p> Signup and view all the answers

    Which of the following correctly defines a 'codon'?

    <p>A three-base sequence in mRNA that codes for an amino acid</p> Signup and view all the answers

    What is the primary focus of proteomics in biology?

    <p>Comprehensive characterization of an organism's complete set of proteins</p> Signup and view all the answers

    What is the definition of polymorphism in genetics?

    <p>Variations in a DNA sequence among individuals</p> Signup and view all the answers

    Which statement best describes diploid cells?

    <p>Cells that carry two copies of each genome</p> Signup and view all the answers

    What best describes the function of exons in a gene?

    <p>Coding regions of DNA that are translated into proteins</p> Signup and view all the answers

    What is one application of molecular diagnostics?

    <p>Predict disease progression</p> Signup and view all the answers

    What characterizes the structure of human nuclear DNA?

    <p>Diploid genome packaged in pairs of chromosomes</p> Signup and view all the answers

    What enzyme is primarily responsible for the separation of DNA strands during replication?

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

    In DNA replication, what is the outcome of the pairing process catalyzed by DNA polymerase?

    <p>Production of complementary DNA strands</p> Signup and view all the answers

    What is a significant role of mitochondrial DNA compared to nuclear DNA?

    <p>Independent replication and inheritance</p> Signup and view all the answers

    Which characteristic describes a karyotype?

    <p>A visual representation of chromosomes arranged by size</p> Signup and view all the answers

    What defines the genetic units of human DNA in terms of chromosomal arrangement?

    <p>22 pairs of homologous chromosomes and 2 sex chromosomes</p> Signup and view all the answers

    What does the term 'biological blueprint' refer to in genetics?

    <p>The structure of DNA</p> Signup and view all the answers

    Which statement regarding nitrogen bases in DNA and RNA is correct?

    <p>Adenine pairs with Thymine in DNA and Uracil in RNA.</p> Signup and view all the answers

    What is the correct orientation of the DNA double helix structure?

    <p>Strands are oriented in opposite directions.</p> Signup and view all the answers

    Which of the following accurately describes a haplotype?

    <p>The combination of alleles at multiple loci on the same chromosome.</p> Signup and view all the answers

    In the context of genetic inheritance, which statement is true?

    <p>Natural polymorphisms can lead to higher mutation rates.</p> Signup and view all the answers

    Which base pairing in DNA follows Watson-Crick rules?

    <p>Cytosine pairs with Guanine.</p> Signup and view all the answers

    Which of the following statements about nucleotide bases is incorrect?

    <p>Purines include both Cytosine and Uracil.</p> Signup and view all the answers

    Which statement regarding the base pairings in DNA is true?

    <p>Base pairs are formed by hydrogen bonds between purines and pyrimidines.</p> Signup and view all the answers

    What is the significance of the 5' and 3' ends of a DNA strand?

    <p>The 5' end contains a phosphate group while the 3' end has a hydroxyl group.</p> Signup and view all the answers

    Qual es le function principal del RNA messaggero (mRNA)?

    <p>Facilitar le translation del codice genetico</p> Signup and view all the answers

    Quo significa splice in le contexto de mRNA?

    <p>Removal de introns durante le processing</p> Signup and view all the answers

    Quo caracteriza le codon AUG in le sequenza de codon usage?

    <p>Es le codon de initiation</p> Signup and view all the answers

    Que es le consequence del poliadennylation in RNA?

    <p>Stabilisar le mRNA contra degradation</p> Signup and view all the answers

    Quo face le base uracilo in RNA comparate a thymine in DNA?

    <p>Replace thymine pro formar un RNA</p> Signup and view all the answers

    Quo indica le sequenza de peptide 'Met-Lcu-Glv-Ser-His'?

    <p>Le sequenza de amino acidos resultante de translation</p> Signup and view all the answers

    Quo es lo que se refere al processus de transcription in biologia molecular?

    <p>Converte DNA in mRNA</p> Signup and view all the answers

    Que descrive le function de exons in un gene?

    <p>Contiene information genetic pro le formation de proteínas</p> Signup and view all the answers

    Qual es le significato de un codon in mRNA?

    <p>Un combinate de 3 nucleotides que codifica pro un aminoacid</p> Signup and view all the answers

    Que resulta de un different sequencia de base pairs in un gene?

    <p>Causa le formation de un diferente proteína</p> Signup and view all the answers

    Qual es le proposita del dogma central de biologia molecular?

    <p>Descrever le pathway genetic de replicazione a traducción</p> Signup and view all the answers

    Quo es significante de 5' e 3' finos de un filamento de DNA?

    <p>Indica le direction de replication e transcription</p> Signup and view all the answers

    Qual es le effecto de introns in genes?

    <p>Contribue al production de mRNA spliceado</p> Signup and view all the answers

    Qual es le resultato de le processus de translation?

    <p>Proteínas se forma basante sur le information de mRNA</p> Signup and view all the answers

    Qual parte del DNA remane in le nucleus?

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

    Qualle passo in le isolation de DNA occurre post le lysis de cellulas nucleate?

    <p>Denaturar digestiones de proteinas</p> Signup and view all the answers

    Quel methoda usa un extraction organic in le isolation de DNA?

    <p>Extraction phenol/chloroform</p> Signup and view all the answers

    Quel passo in le isolation de DNA involve le removal de contaminantes?

    <p>Separar contaminantes de DNA</p> Signup and view all the answers

    Qualle declaration super le chromosomal crossover es correcte?

    <p>Es importante pro le reorganization genética</p> Signup and view all the answers

    Qualle de le sequente es un passo pro resuspender DNA in le buffer final?

    <p>Resuspendere DNA in le buffer final</p> Signup and view all the answers

    Qualle de le sequente non es un methoda de isolation de DNA?

    <p>Digestiones de acidos nucleicos</p> Signup and view all the answers

    Qual parte del processo de isolation de DNA concerne le separation de WBCs?

    <p>Separar WBCs de RBCs</p> Signup and view all the answers

    Qual es le principal function de chromosomes durante le prophase I de meiosis?

    <p>Exchanger porciones de DNA</p> Signup and view all the answers

    Qual es le modo correct de conservar DNA pro un tempore a longo?

    <p>In buffer TE a -20°C a -70°C</p> Signup and view all the answers

    Le qualitate de quales fontes de sample pote esser usate pro isolation de acidos nucleic?

    <p>Tessito con nucleus</p> Signup and view all the answers

    Qual es le consequence de congelar sanguine total durante le conservation?

    <p>Le DNA sufre deterioramento</p> Signup and view all the answers

    In qual condition debe RNA esser conservate?

    <p>In aqua ultrapure libere de RNase</p> Signup and view all the answers

    Quo sucede quando regiones correspondent de chromosomes non se recombina correctemente?

    <p>Se origina errores genetic</p> Signup and view all the answers

    What is the primary outcome of meiosis in terms of cell type generated?

    <p>Generates four haploid gametes</p> Signup and view all the answers

    In which phase does recombination between homologous chromosomes primarily occur during meiosis?

    <p>Prophase I</p> Signup and view all the answers

    Which of the following best describes the term 'haploid' in relation to gametes?

    <p>Contains one set of chromosomes</p> Signup and view all the answers

    What is the purpose of lysing WBCs in DNA isolation methods?

    <p>To release nuclear DNA from cytoplasm</p> Signup and view all the answers

    What is the function of denaturing proteins during the DNA isolation process?

    <p>To remove protein contamination from DNA</p> Signup and view all the answers

    Which step is performed after separating contaminants in the DNA isolation procedure?

    <p>Precipitating DNA</p> Signup and view all the answers

    What characterizes the chromosomes involved in meiotic recombination?

    <p>Chromosomes are homologous pairs from each parent</p> Signup and view all the answers

    Which statement best describes a key step in the basic procedure of isolating DNA?

    <p>Precipitate DNA with alcohol</p> Signup and view all the answers

    What is the first step to calculate nucleic acid yield?

    <p>Multiply DNA/RNA concentration by the volume of hydrating solution</p> Signup and view all the answers

    Which of the following correctly describes the recognition sequences of bacterial enzymes?

    <p>They usually consist of 4 to 6 bases but can be longer</p> Signup and view all the answers

    Which of the following accurately describes the primary use of DNA microarrays?

    <p>To examine gene expression levels simultaneously</p> Signup and view all the answers

    What defines the specific functionality of cohesive and blunt ends in DNA manipulation?

    <p>Cohesive ends have overhangs that facilitate easier joining</p> Signup and view all the answers

    What does the calculation of nucleic acid yield mainly depend on?

    <p>The concentration of DNA/RNA and its hydration volume</p> Signup and view all the answers

    Which of the following statements about recognition sequences is true?

    <p>Recognition sequences are generally palindromic</p> Signup and view all the answers

    How is the DNA yield determined using spectrophotometric methods?

    <p>By multiplying DNA concentration from UV measurement by the hydration volume</p> Signup and view all the answers

    Which characteristic of DNA microarrays allows them to monitor gene expression?

    <p>They can arrange thousands of genes on a solid support</p> Signup and view all the answers

    What process occurs when two chromosomes exchange genetic material during prophase I of meiosis?

    <p>Chromosomal crossover</p> Signup and view all the answers

    Which storage condition is appropriate for preserving DNA for the long term?

    <p>In TE buffer at -70°C</p> Signup and view all the answers

    What is the main advantage of using agarose gel electrophoresis in nucleic acid analysis?

    <p>It separates DNA fragments based on charge and size</p> Signup and view all the answers

    Which method involves chemical degradation for determining the order of nucleotides in a DNA molecule?

    <p>Maxam-Gilbert</p> Signup and view all the answers

    Which tissue sample is NOT suitable for nucleic acid extraction?

    <p>Whole blood that has been frozen</p> Signup and view all the answers

    Which of the following is NOT a typical application of gene cloning using recombinant DNA technology?

    <p>Generating microarrays</p> Signup and view all the answers

    Which method is commonly used to measure DNA quantity and quality?

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

    What does palindromic DNA sequence imply when considering both strands of DNA?

    <p>The same sequence on both strands read in either direction</p> Signup and view all the answers

    What is the main reason for using EDTA when collecting blood for DNA isolation?

    <p>To chelate metal ions and preserve DNA integrity</p> Signup and view all the answers

    In which sequencing method are single molecules of DNA sequenced in real time?

    <p>Next generation sequencing</p> Signup and view all the answers

    What characterizes the molecular size of nucleic acids during analysis?

    <p>It can vary due to genetic recombination</p> Signup and view all the answers

    What role does a vector, such as a plasmid, play in gene cloning?

    <p>It serves as a transport mechanism for DNA fragments.</p> Signup and view all the answers

    What condition is NOT recommended for storing RNA?

    <p>At room temperature in saline</p> Signup and view all the answers

    Which of the following technologies is NOT associated with pyrosequencing?

    <p>Use of fluorescent primers</p> Signup and view all the answers

    What is the formula to calculate the concentration of DNA in micrograms per milliliter based on absorbance at 260 nm?

    <p>[DNA] = A260 X dilution factor X 50 ug/ml</p> Signup and view all the answers

    At what wavelength do proteins primarily absorb UV light?

    <p>280 nm</p> Signup and view all the answers

    What is considered a good purity ratio for nucleic acids measured as A260/A230?

    <p>1.8-2.0</p> Signup and view all the answers

    What dilution factor is used when calculating RNA concentration from an absorbance reading of 0.500?

    <p>1:10</p> Signup and view all the answers

    What is the molar extinction coefficient factor used for RNA when calculating concentration?

    <p>40 ug/ml</p> Signup and view all the answers

    When determining nucleic acid concentration using UV spectrophotometry, what is the typical result of a dilution affecting absorbance?

    <p>Lower absorbance at higher dilution</p> Signup and view all the answers

    What is the significance of an A260 reading that results in a concentration of 200 ug/ml for DNA?

    <p>Reflects normal absorbance range for nucleic acids</p> Signup and view all the answers

    Which option correctly identifies the measurement used to assess nucleic acid purity?

    <p>A260/A230 ratio</p> Signup and view all the answers

    What is one of the primary uses of DNA microarrays?

    <p>Gene expression studies</p> Signup and view all the answers

    What is a key characteristic of the arrangement of DNA sequences on a DNA microarray?

    <p>Fixed and predetermined layout</p> Signup and view all the answers

    Which of the following describes a palindromic sequence in DNA?

    <p>A sequence that reads the same in both DNA strands</p> Signup and view all the answers

    Which statement accurately depicts the function of special instrumentation in DNA microarray technology?

    <p>To generate and analyze microarrays</p> Signup and view all the answers

    What is one potential application of using DNA microarrays?

    <p>Pharmacogenetics for drug discovery</p> Signup and view all the answers

    What does the hybridization technology in DNA microarrays primarily allow for?

    <p>Simultaneous monitoring of gene expression levels</p> Signup and view all the answers

    In gene cloning, what is the primary aim of isolating a defined DNA sequence?

    <p>To amplify the DNA for various applications</p> Signup and view all the answers

    What factor distinguishes the microarray technique when examining thousands of genes?

    <p>Simultaneous analysis across a wide array of genes</p> Signup and view all the answers

    What primarily influences the movement of DNA particles through a gel during electrophoresis?

    <p>The size of DNA particles and gel pore size</p> Signup and view all the answers

    Which factor does not directly affect the mobility of DNA in gel electrophoresis?

    <p>Presence of ribosomal RNA</p> Signup and view all the answers

    What is the primary purpose of the Southern blot technique?

    <p>To detect specific DNA sequences</p> Signup and view all the answers

    In Pulsed Field Gel Electrophoresis (PFGE), what is one capability that distinguishes it from conventional gel electrophoresis?

    <p>Analysis of DNA fragments up to 100 kb</p> Signup and view all the answers

    What role does an increase in pH serve during the Southern blot process?

    <p>Denatures DNA in the gel</p> Signup and view all the answers

    What is a common method for transferring DNA to a membrane during the Southern blot procedure?

    <p>Capillary action with a high salt solution</p> Signup and view all the answers

    Which of the following is essential for a labeled complementary probe in the Southern blot technique?

    <p>Facilitates hybridization with specific DNA fragments</p> Signup and view all the answers

    Which element is NOT commonly analyzed in determining DNA mobility through gels?

    <p>Concentration of proteins in the gel</p> Signup and view all the answers

    What temperature range is generally used for primer annealing in molecular biology processes?

    <p>50-60°C</p> Signup and view all the answers

    Which of the following best describes microsatellites in terms of structure?

    <p>Short sequences of tandem repeats with variable lengths</p> Signup and view all the answers

    What is the main process occurring during the extension stage at 72°C?

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

    Which type of polymorphism is characterized by variations in the number of repeating units of a specific sequence?

    <p>Microsatellite polymorphism</p> Signup and view all the answers

    What is the purpose of using fluorescent in-situ hybridization (FISH) in genetic analysis?

    <p>To visualize the location of specific DNA sequences in cells</p> Signup and view all the answers

    What is a common characteristic of tandem repeats found in minisatellites?

    <p>They vary in length from 14 to 100 base pairs.</p> Signup and view all the answers

    How does the denaturation of DNA occur in the presence of salt during genetic processes?

    <p>Through heating above the melting temperature</p> Signup and view all the answers

    What defines the content of SNPs in the context of genetic variation?

    <p>They are alterations at a single nucleotide position.</p> Signup and view all the answers

    What characterizes real-time PCR (qPCR) compared to qualitative PCR?

    <p>It detects a fluorescent reporter molecule after each cycle.</p> Signup and view all the answers

    What is the primary function of Nucleic Acid Sequence Based Amplification (NASBA)?

    <p>To amplify RNA and rRNA sequences.</p> Signup and view all the answers

    Which statement accurately describes Strand Displacement Amplification (SDA)?

    <p>It is based on the principle of strand displacement in nucleic acid synthesis.</p> Signup and view all the answers

    How many copies of the target DNA sequence are produced after the second synthesis cycle in DNA amplification using PCR?

    <p>Four copies of the target sequence.</p> Signup and view all the answers

    What is a distinct feature of qualitative PCR techniques?

    <p>They primarily focus on determining the presence or absence of a specific nucleic acid.</p> Signup and view all the answers

    Which aspect of DNA amplification using Polymerase Chain Reaction (PCR) is critical for the determination of results?

    <p>The sequence of primers used in the reaction.</p> Signup and view all the answers

    Which of the following is a potential application for techniques like NASBA?

    <p>To amplify specific RNA sequences for diagnostic purposes.</p> Signup and view all the answers

    What is a common misconception about the timing of DNA amplification cycles?

    <p>All DNA strands are amplified simultaneously in each cycle.</p> Signup and view all the answers

    What is the purpose of heat denaturation in target amplification techniques?

    <p>To separate DNA strands for replication</p> Signup and view all the answers

    Which method utilizes a solid phase for signal amplification through chemiluminescence?

    <p>Hybrid capture</p> Signup and view all the answers

    What factor is primarily responsible for the migration of negatively charged DNA toward the anode during electrophoresis?

    <p>The electric field applied</p> Signup and view all the answers

    In the context of DNA migration during electrophoresis, what is meant by 'inversely proportional to log10 of molecular size'?

    <p>DNA migration rate decreases as size increases</p> Signup and view all the answers

    What role do hybrid probes play in branched chain DNA amplification?

    <p>They provide a signal amplification mechanism</p> Signup and view all the answers

    Which type of matrix is commonly used in electrophoresis to separate nucleic acids?

    <p>Agarose or polyacrylamide</p> Signup and view all the answers

    What is the relationship between pore size and the separation efficiency of DNA fragments in gel electrophoresis?

    <p>Larger pore sizes impede the movement of larger fragments</p> Signup and view all the answers

    Which factor is least likely to affect the migration rate of DNA in electrophoresis?

    <p>The buffer solution's pH</p> Signup and view all the answers

    Which factor primarily affects the migration speed of DNA fragments in gel electrophoresis?

    <p>Size of the DNA fragments</p> Signup and view all the answers

    What is the primary purpose of using a labeled complementary probe in Southern blotting?

    <p>To specifically detect target DNA sequences</p> Signup and view all the answers

    In pulsed field gel electrophoresis (PFGE), what is the maximum size of DNA fragments that can be analyzed?

    <p>100 kb</p> Signup and view all the answers

    How does temperature influence the process of gel electrophoresis?

    <p>It impacts the rate of DNA denaturation in the gel.</p> Signup and view all the answers

    Which characteristic is true about the buffer used in electrophoresis?

    <p>It must maintain a constant pH during the process.</p> Signup and view all the answers

    What occurs to the DNA during the Southern blotting transfer process?

    <p>DNA moves to the membrane via capillary action.</p> Signup and view all the answers

    What is the first step in the Western blotting procedure outlined?

    <p>Protein run on SDS-polyacrylamide gel electrophoresis</p> Signup and view all the answers

    What process is used to transfer DNA onto a nitrocellulose membrane?

    <p>Capillary action</p> Signup and view all the answers

    Which component is used to denature DNA in the Western blotting protocol?

    <p>Alkaline solution</p> Signup and view all the answers

    Which of the following describes the role of the labeled probe in the Western blotting process?

    <p>It binds to complementary DNA sequences on the gel.</p> Signup and view all the answers

    What is the purpose of using a blocking solution in Western blotting?

    <p>To prevent non-specific binding of antibodies</p> Signup and view all the answers

    After the proteins are electrophoresed, what is the next procedural step in Western blotting?

    <p>Proteins are transferred to a membrane.</p> Signup and view all the answers

    What is the role of secondary antibodies in the Western blotting technique?

    <p>To assist in signal amplification for detection</p> Signup and view all the answers

    Which of the following is true regarding the alkaline solution used in the Western blotting process?

    <p>It denatures the DNA prior to transfer.</p> Signup and view all the answers

    What does the term 'stringency' refer to in hybridization processes?

    <p>The conditions under which hybridization takes place</p> Signup and view all the answers

    What is the primary purpose of a southern blot technique?

    <p>To identify specific DNA sequences</p> Signup and view all the answers

    In a northern blot, which component is primarily detected?

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

    Which technique uses capillary action for transferring RNA to a membrane?

    <p>Northern blot</p> Signup and view all the answers

    What is the role of a labeled complementary probe in molecular blotting techniques?

    <p>To visualize the target nucleic acid after transfer</p> Signup and view all the answers

    What is the primary mechanism used by branched chain DNA (bDNA) to amplify signals?

    <p>Hybrid probes in chemiluminescence</p> Signup and view all the answers

    Which blots are specifically designed for quick analyses of DNA and RNA without determining size?

    <p>Dot and slot blots</p> Signup and view all the answers

    Which factor does NOT affect the migration rate of DNA during electrophoresis?

    <p>Gel temperature</p> Signup and view all the answers

    Which visualization method is NOT commonly used in southern blotting?

    <p>Western blotting antibodies</p> Signup and view all the answers

    What is a key characteristic of reverse dot blots?

    <p>They are essential for detecting human mutations</p> Signup and view all the answers

    How does the charge of DNA influence its movement in an electric field?

    <p>Negatively charged DNA migrates toward the anode</p> Signup and view all the answers

    What does the migration rate of DNA correspond to in terms of its characteristics?

    <p>Inversely proportional to the log of molecular size</p> Signup and view all the answers

    What role does the porosity of the gel matrix play in electrophoresis?

    <p>It determines the size of DNA particles that can migrate</p> Signup and view all the answers

    Which of the following statements best describes electrophoresis of nucleic acids?

    <p>Migration occurs through a sieve-like gel matrix</p> Signup and view all the answers

    What analogy is used to describe the speed of DNA migration in electrophoresis?

    <p>Bunnies migrate faster than tortoises</p> Signup and view all the answers

    Which parameter is vital in determining the direction of DNA migration in gel electrophoresis?

    <p>The charge of the nucleic acid</p> Signup and view all the answers

    What components are involved in one cycle of polymerase chain reaction (PCR)?

    <p>Denaturation, annealing, extension</p> Signup and view all the answers

    What does the migration rate of a macromolecule through a gel matrix primarily depend on?

    <p>All of the above</p> Signup and view all the answers

    What is the chance of an individual being affected by an autosomal dominant trait if they have one affected parent?

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

    Which step in RT-PCR is not included in the typical process?

    <p>DNA isolation</p> Signup and view all the answers

    X-linked recessive traits are more commonly expressed in which group?

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

    What does a haploid copy number in the human genome refer to?

    <p>A single set of chromosomes</p> Signup and view all the answers

    What kind of structure is suggested by the approximate length of the human genome?

    <p>A complex folded structure</p> Signup and view all the answers

    What does a normal and mutant banding pattern indicate about an individual's genetics?

    <p>Heterozygosity for a trait</p> Signup and view all the answers

    Which term refers to the sequences within a gene that are expressed as proteins?

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

    What type of genetic inheritance is characterized by a single mutant allele being sufficient to express the trait?

    <p>Autosomal dominant</p> Signup and view all the answers

    What specific DNA sequences do restriction endonucleases identify for cleavage?

    <p>Palindromic sequences</p> Signup and view all the answers

    Which method is primarily used to detect proteins in a sample?

    <p>Western blotting</p> Signup and view all the answers

    In the context of DNA analysis, what does a higher A260/A280 ratio generally indicate?

    <p>High purity of DNA</p> Signup and view all the answers

    Which of the following options typically contains chlorophyll?

    <p>Green bean, squash, and asparagus</p> Signup and view all the answers

    What characterizes a compound homozygous genetic condition?

    <p>Two or more alleles at multiple loci</p> Signup and view all the answers

    Which of the following would likely not be a role of splice sites during gene expression?

    <p>Translating mRNA into proteins</p> Signup and view all the answers

    What type of genetic material is identified by Southern Blotting?

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

    Which statement accurately describes the composition of the human genome?

    <p>It is diploid with a total of 23 chromosome pairs.</p> Signup and view all the answers

    What factors influence the migration rate of a macromolecule during gel electrophoresis?

    <p>Thickness of the agarose gel, molecular charge, and size of the molecule</p> Signup and view all the answers

    In a pedigree chart, if one parent is heterozygous and the other is homozygous recessive, what is the probability of their offspring displaying the dominant trait?

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

    What is the primary purpose of Western Blotting in molecular biology?

    <p>To identify specific proteins</p> Signup and view all the answers

    What is the absorbance reading at 260 nm for a 1:100 dilution of a DNA sample if the total amount of DNA in the original sample is calculated to be 0.215 ug/mL?

    <p>0.430</p> Signup and view all the answers

    When performing a spectrophotometric analysis, what would the amount of DNA contained in a 0.4 ml sample be if the 1:50 dilution gives an OD260 reading of 0.041?

    <p>41 ug</p> Signup and view all the answers

    What is the first step of a polymerase chain reaction (PCR) cycle?

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

    What type of macromolecule does Northern Blotting primarily identify?

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

    Which of the following concentrations would correspond to an absorbance reading of 0.210 for a 1:200 dilution of an RNA sample?

    <p>1680 ug/ml</p> Signup and view all the answers

    What is the correct calculation for the DNA concentration if the absorbance at 260 nm for a 1:100 dilution sample is found to be 0.430?

    <p>1720 ug/mL</p> Signup and view all the answers

    What major structural characteristic distinguishes the human genome from bacterial genomes?

    <p>It consists of multiple linear chromosomes.</p> Signup and view all the answers

    If a 1:50 dilution of a DNA sample gives an OD260 reading of 0.041, how would you determine the concentration in ug/mL?

    <p>Multiply the OD260 by the dilution factor</p> Signup and view all the answers

    Which of the following statements best describes the process of obtaining a concentration for a nucleic acid sample using spectrophotometric analysis?

    <p>The absorbance reading must be corrected for dilution to determine concentration.</p> Signup and view all the answers

    In determining RNA concentration, how would an absorbance of 0.210 from a 1:200 dilution translate to total concentration?

    <p>1680 ug/ml</p> Signup and view all the answers

    What is the expected concentration of DNA in the original sample if a 1:50 dilution has an OD260 reading of 0.041?

    <p>0.205 ug/mL</p> Signup and view all the answers

    What is the primary role of Taq polymerase in DNA amplification?

    <p>To amplify DNA strands</p> Signup and view all the answers

    Why are X-linked traits generally more prevalent in males than in females?

    <p>Males have only one X chromosome</p> Signup and view all the answers

    What does heterozygous refer to in the context of genetic patterns?

    <p>Carrying one normal and one mutant gene</p> Signup and view all the answers

    Which statement correctly describes autosomal recessive traits?

    <p>They typically skip generations</p> Signup and view all the answers

    What role do exons play in the structure of a gene?

    <p>They code for amino acids</p> Signup and view all the answers

    What does the presence of introns in a gene indicate?

    <p>They are transcribed into mRNA but removed before translation</p> Signup and view all the answers

    What is essential for the successful execution of reverse transcription PCR (RT-PCR)?

    <p>Isolation of RNA from the sample</p> Signup and view all the answers

    Why is the inheritance of X-linked traits not seen in father to son transmission?

    <p>Sons inherit Y chromosomes from their fathers</p> Signup and view all the answers

    Study Notes

    Molecular Diagnostics & Genetics Key Terminology

    • Agarose: Gel-forming polysaccharide derived from seaweed, used in various biological applications.
    • Molecular Diagnostics: Techniques using DNA, RNA, or mRNA to identify or characterize diseases caused by infections or genetic abnormalities.
    • Allele: Different forms of a gene occurring at a specific locus on a chromosome.
    • Cell Nucleus: Contains the genetic material of the cell, housing DNA.
    • Codon: A sequence of three nucleotide bases in mRNA that specifies an amino acid during protein synthesis.
    • Diploid: Cells containing two complete sets of chromosomes, one from each parent.
    • Epigenetics: Study of changes in gene activity regulation and expression not linked to DNA sequence alterations.
    • Exon: Portions of a gene coding for proteins, which are translated during protein synthesis.
    • Gene Expression: The process through which specific genes are activated to produce proteins, tightly regulated within the cell.
    • Genetic Code: The set of rules defining how sequences of nucleotides correspond to specific amino acids in proteins.
    • Genome: The complete set of DNA, including all of its genes, within an organism.
    • Genotype: The genetic makeup of an individual, represented by the alleles at specific loci.
    • Haploid: Cells, such as gametes, containing a single set of chromosomes, crucial for sexual reproduction.
    • Haplotype: A group of alleles inherited together from a single parent on a single chromosome.
    • Heterozygous: Having two different alleles at a particular genetic locus.
    • Homozygous: Possessing two identical alleles at a specific locus.
    • Intron: Non-coding sequences found between exons within a gene.
    • Ligation: The process of joining two DNA molecule ends, often used in cloning.
    • Mutations: Permanent alterations in the DNA sequence, which can affect gene function and expression.
    • Penetrance: The likelihood that a specific genotype will lead to the expression of a particular phenotype.
    • Phenotype: The observable traits or characteristics of an organism, resulting from the interaction of its genotype and environment.
    • Polymorphism: Variations in the nucleotide sequence among individuals, contributing to genetic diversity.
    • Proteins: Large biomolecules made up of amino acids that perform a wide array of functions within organisms.
    • Protein Expression: Process where different proteins are generated in cells based on their specific functions.
    • Proteomics: Comprehensive study of all the proteins expressed by an organism, providing insight into cellular functions.
    • RFLP (Restriction Fragment Length Polymorphism): Variances in the sizes of DNA fragments produced by restriction enzyme digestion, useful in genetic analysis.
    • Sequence: The specific order of nucleotide bases along a DNA strand, crucial for genetic encoding.
    • STR (Short Tandem Repeats): Repeated short DNA sequences (2-5 base pairs) found throughout the genome, useful in genetic profiling.
    • Telomere: Repetitive DNA sequences located at the ends of chromosomes, protecting them during cell division.
    • Transcription: The process in which genetic information from DNA is copied into mRNA, facilitated by the RNA polymerase enzyme.
    • Transcriptome: The complete set of RNA molecules transcribed in a specific cell, reflecting gene expression at a given time.

    Molecular Diagnostics Application

    • Molecular diagnostics are essential for disease detection, prediction, paternity, forensic analysis, gene therapy, and drug design.
    • Key applications include identifying the cause of disease (diagnosis), predicting disease progression, and analyzing DNA for paternity and forensic purposes.

    DNA Replication (Semi-Conservative)

    • DNA replication involves the separation of strands by helicase enzyme.
    • DNA polymerase facilitates the pairing of bases on each strand with new complementary bases.
    • This process results in the production of two new DNA strands, each an exact duplicate of the original DNA.

    The Chemical Basis of Heredity

    • DNA serves as the biological "blueprint" for life, providing the necessary information for cellular functions.
    • It allows cells to live, grow, differentiate, and replicate, ensuring both consistency and variability in genetic traits.

    Genetic Units of Human DNA

    • Human DNA consists of nuclear DNA (diploid genome) and mitochondrial DNA.
    • Nuclear DNA is packed in 23 pairs of chromosomes, including 22 homologous pairs (autosomes) and 2 sex chromosomes (XX or XY).
    • The human genome contains approximately 6 billion base pairs and around 30,000 genes.

    Karyotype Analysis

    • Karyotyping assesses the normality of chromosome number and structure.
    • Chromosomes are numbered by size and the position of the centromere, with regions labeled as short arm (p) and long arm (q).
    • A pattern is created based on staining intensity or fluorescence to identify chromosomal abnormalities.

    Mitochondrial DNA

    • Mitochondrial DNA (non-nuclear) contains 16,569 base pairs and 37 genes.
    • It exhibits a higher mutation rate and possesses 128 naturally occurring polymorphisms.
    • Transmission occurs solely through maternal inheritance.

    DNA/RNA Structure

    • Composed of two types of nitrogen bases: purines and pyrimidines.
    • Purines: Adenine (A), Guanine (G) present in both DNA and RNA.
    • Pyrimidines: Cytosine (C) and Thymine (T) found in DNA, with Uracil (U) replacing Thymine in RNA.

    Base Pairing and DNA Double Helix

    • Hydrogen bonds form between pyrimidines and purines, adhering to Watson-Crick base pairing rules: A=T (or A=U in RNA), G≡C.
    • The DNA double helix is oriented in opposite directions with a 5' end (beginning) and a 3' end (end).
    • Nucleotide bases pair to create "base pairs," ensuring specific pairing sequences for genetic stability.

    Human Gene Structure

    • Genes consist of exons separated by introns, with sequences encoding information for protein synthesis.
    • Variations in sequences lead to the production of different proteins.

    The Central Dogma of Molecular Biology

    • Describes the flow of genetic information: DNA → RNA → Protein.
    • Involves three processes: replication, transcription, and translation.

    Translation and Genetic Code

    • Each set of three nucleotides (codon) on mRNA corresponds to a specific amino acid.
    • Codons determine the sequence of amino acids in a polypeptide chain, forming proteins.

    Transcription

    • mRNA is formed as a complementary sequence to the DNA template.
    • In RNA, uracil (U) replaces thymine (T) found in DNA.
    • mRNA processing involves:
      • Splicing: removing introns.
      • Capping: modifying the 5' end of mRNA.
      • Polyadenylation: adding adenine nucleotides to the 3' end, creating a poly-A tail.
    • Introns remain in the nucleus while exons exit.

    Molecular Techniques for DNA Isolation

    • Basic steps in isolating DNA from clinical specimens include:
      • Separating white blood cells from red blood cells.
      • Lysing white blood cells to release DNA.
      • Denaturing or digesting proteins.
      • Separating contaminants from DNA.
      • Precipitating DNA if needed and resuspending in buffer.

    DNA Isolation Methods

    • Techniques include:
      • Liquid phase organic extraction (phenol/chloroform).
      • Liquid phase non-organic extraction.
      • Solid phase procedures for purification.

    Chromosomal Crossover (Genetic Recombination)

    • Occurs during prophase I of meiosis when paired chromosomes exchange DNA segments.
    • Matching regions break and reconnect, leading to gene exchange.

    Sample Source and Storage

    • DNA can be isolated from any nucleated tissue, with blood collected in anticoagulants (EDTA preferred).
    • Storage conditions for DNA:
      • In TE buffer at 4°C for weeks or at -20°C to -70°C for long-term preservation.
    • RNA should be stored in RNase-free ultrapure water at -70°C.

    Meiosis and Genetic Recombination

    • Meiosis occurs during gamete formation, generating four haploid gametes from a diploid progenitor cell.
    • Meiotic recombination frequently involves homologous chromosomes exchanging genetic material.
    • Chromosomal crossover happens during prophase I of meiosis, where physical regions of paired chromosomes break and reconnect to form new gene combinations.

    Molecular Techniques for DNA Isolation

    • Basic steps in isolating DNA from clinical specimens include separating white blood cells (WBCs) from red blood cells (RBCs), lysing WBCs, denaturing digestive proteins, separating contaminants from DNA, and resuspending DNA in a buffer.
    • DNA isolation methods include liquid phase organic extraction (phenol/chloroform), liquid phase non-organic extraction, and solid phase procedures.

    Nucleic Acid Analysis

    • Nucleic acid quantity and quality measurement techniques include UV spectrophotometry, agarose gel electrophoresis, fluorometry, and colorimetric blotting.
    • DNA and RNA absorb light at 260 nm; proteins absorb at 280 nm, crucial for determining nucleic acid purity.
    • For DNA and RNA quantitation:
      • DNA concentration = A260 × dilution factor × 50 µg/ml
      • RNA concentration = A260 × dilution factor × 40 µg/ml
    • A260/A230 ratio is used as a measure of nucleic acid purity, with a ratio of 1.8–2.0 indicating high purity.

    Restriction Endonucleases

    • Bacterial enzymes that cut specific DNA sequences, referred to as "molecular scalpels."
    • They recognize specific short recognition sequences (usually palindromes), often 4 to 6 bases long.

    DNA Microarrays

    • DNA microarrays use hybridization technology for examining gene expression across thousands of genes simultaneously.
    • They play significant roles in gene expression studies, disease diagnostics, and pharmacogenetics.
    • Special equipment is required for microarray generation and analysis.

    Gene Cloning (Recombinant DNA Technology)

    • Involves isolating and amplifying a defined DNA sequence using vectors (e.g., plasmids) and appropriate host organisms like E. coli.

    DNA Sequencing Techniques

    • Several methods for determining the nucleotide order in DNA:
      • Maxam-Gilbert (chemical degradation)
      • Sanger method (dideoxy chain termination)
      • Pyrosequencing (sequence by synthesis)
      • Next-generation sequencing (real-time sequencing of single DNA molecules) using technologies from Pacific Biosciences and Oxford Nanopore.

    DNA Microarrays (DNA Chip)

    • Utilizes hybridization technology for examining gene expression.
    • DNA sequences are arranged on a solid support, enabling analysis.
    • Each microarray contains thousands of genes to monitor expression levels simultaneously.
    • Applications include gene expression studies, disease diagnosis, and pharmacogenetics (drug discovery).
    • Requires specialized instrumentation for the creation and analysis of microarrays.
    • Palindromic sequences remain the same when read in either direction (e.g., 5' - GGTACC - 3' and 3' - CCATGG - 5').

    Gene Cloning (Recombinant DNA Technology)

    • Focuses on isolating and amplifying specific DNA sequences.
    • Primer annealing occurs at temperatures between 50-60°C.
    • Polymerase chain reaction (PCR) involves extending primers at 72°C to synthesize full-length genes.
    • Each PCR cycle doubles the amount of DNA, exponentially increasing genetic material.

    Fluorescent In-Situ Hybridization (FISH)

    • Involves the hybridization of a fluorescent DNA probe to complementary DNA in preserved tissues or cells.

    Real-Time PCR / Quantitative PCR (qPCR)

    • A dual qualitative and quantitative technique for detecting fluorescent reporters after each amplification cycle.

    Nucleic Acid Sequence Based Amplification (NASBA)

    • Amplification technique targeting RNA and rRNA specifically.
    • Used for the direct detection of RNA viruses, such as HCV and HIV.

    Strand Displacement Amplification (SDA)

    • Amplification method using heat denaturation, annealing, and extension.
    • Generates an altered target with restriction endonuclease recognition sites.

    Branched Chain DNA (bDNA)

    • Utilizes a series of hybrid probes to amplify signals through chemiluminescence.
    • Enables detection of specific RNA sequences.

    Electrophoresis of Nucleic Acids

    • Method separates nucleic acids based on size and charge through agarose or polyacrylamide gel.
    • DNA migrates toward the positively charged anode due to its negative charge.
    • Migration rate depends on the gel's matrix type, nucleic acid charge, and size.

    Factors Affecting Migration Rate

    • Type and porosity of the gel, net charge of the molecule, DNA conformation, electric field strength, and temperature.
    • Larger DNA fragments migrate slower due to difficulty navigating small gel pores, while smaller fragments move faster.

    Blotting Techniques

    • Southern Blot: Used to detect specific DNA sequences, where DNA is denatured in gel and transferred to a membrane by capillary action.
    • High salt solutions facilitate the transfer of DNA to membranes for subsequent analysis.

    Branched Chain DNA (bDNA)

    • Utilizes hybrid probes for signal amplification via chemiluminescence.
    • Designed for detecting specific RNA sequences.

    Electrophoresis of Nucleic Acids

    • Separation of nucleic acids based on size and charge using agarose or polyacrylamide gels.
    • Migration rate is inversely proportional to the logarithm of molecular size (number of base pairs).
    • Negatively charged DNA migrates towards the positively charged anode.

    Factors Affecting Migration Rate

    • Matrix type and gel porosity impact movement through the gel.
    • The net charge of the nucleic acid influences migration speed.
    • DNA conformation plays a role in how easily it can pass through gel pores.
    • Strength of the electric field and gel temperature affect nucleic acid movement.
    • Base composition and the presence of intercalating dyes can alter migration.

    Pulsed Field Gel Electrophoresis (PFGE)

    • Used for analyzing large DNA fragments up to 100 kilobases.
    • Separation achieved by employing a pulsed electric field.
    • Commonly applied in the genotyping of prokaryotes.

    Southern Blot Technique

    • Detects specific DNA sequences by transferring DNA from a gel to a membrane via capillary action in a high-salt solution.
    • DNA is denatured in the gel using an alkaline solution.
    • Utilizes a labeled complementary probe for the detection of target DNA.

    Western Blot Technique

    • Proteins are separated using SDS-polyacrylamide gel electrophoresis (PAGE).
    • Proteins are transferred to membranes via electro-transfer.
    • Membrane is incubated with a primary antibody, followed by a secondary antibody for visualization.
    • Detection can be done using radioactive isotopes, chemiluminescent dyes, or colorimetric techniques.

    Northern Blot Technique

    • Detects specific RNA sequences by transferring RNA to a membrane using a high-salt solution.
    • Labeled complementary probes are employed for detection.

    Dot and Slot Blot Techniques

    • Provide quick analysis of DNA and RNA without determining the size of the target.
    • Applicable for expression, mutation, and amplification analyses.

    Reverse Dot Blots

    • Utilize allele-specific oligonucleotide hybridization for genotyping human mutations.

    Stringency

    • Refers to the conditions under which hybridization occurs, influencing the specificity of the detection process.

    Human Genome and Genetics

    • The human genome is diploid, consisting of 23 chromosome pairs, totaling approximately 6 billion bases.
    • Chromosome structures are linear, not circular.
    • Autosomal dominant traits have a 50% chance of being passed to offspring from a heterozygous parent.

    Molecular Techniques and Principles

    • Electrophoresis migration rates depend on net charge, size of the molecule, and thickness of the gel.
    • Polymerase Chain Reaction (PCR) cycles include denaturation, annealing, and extension.
    • Reverse Transcription PCR (RT-PCR) specifically requires RNA isolation and utilizes reverse transcriptase.

    Genetic Terms

    • A person with normal and mutant banding patterns is termed heterozygous; individuals with identical patterns are homozygous.
    • Coding sequences of genes are referred to as exons, while non-coding regions are known as introns and are spliced out before translation.

    Inheritance Patterns

    • X-linked recessive traits are more common in males due to having only one X chromosome, while females may carry the trait but not express it due to having two X chromosomes.
    • Autosomal recessive traits require two copies of the abnormal gene for expression and can skip generations.

    Experimental Techniques

    • Western blotting is a method used to detect proteins, while Southern blotting identifies DNA and Northern blotting detects RNA.
    • Restriction endonucleases recognize specific palindromic DNA sequences.

    Absorbance and DNA/RNA Quantification

    • Absorbance readings at 260 nm are essential for calculating nucleic acid concentrations.
    • For a 1:100 dilution giving an A260 of 0.430, the DNA concentration can be calculated accurately based on dilution factors.
    • The spectrophotometric analysis of a DNA sample can determine total DNA contained based on dilution and absorbance readings.

    SNP and Contaminants

    • Single Nucleotide Polymorphisms (SNPs) can be determined through sequence variations in genotypes.
    • Contaminants in DNA preparations can be indicated by spectrophotometric slight absorbance differences, such as contamination from chloroform or phenol.

    Pedigree Analysis

    • Pedigrees can illustrate inheritance patterns, helping identify whether traits are autosomal dominant, autosomal recessive, X-linked dominant or recessive, by tracking trait expression across generations.

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    Description

    Test your knowledge on the key terminology and concepts related to molecular diagnostics and genetics. Explore essential terms such as agarose and alleles, and understand their role in identifying diseases. This quiz is perfect for students and professionals in the field of genetics.

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