ch 17 cell bio
90 Questions
12 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

During which phase does DNA synthesis occur?

  • G2 phase
  • G1 phase
  • S phase (correct)
  • M phase
  • What is the process called when microtubules of the mitotic spindle separate the sister chromatids?

  • Chromosomal segregation
  • Cytokinesis
  • Cytoplasmic division
  • Mitosis (correct)
  • What is the division process involving nuclear division and division of the cytoplasm known as?

  • Cytokinesis
  • Mitosis (correct)
  • Interphase
  • Meiosis
  • What is the term for the chromosomes that have duplicated and consist of two sister chromatids?

    <p>Bivalent chromosomes</p> Signup and view all the answers

    What is the term for the gap that separates S phase from the next M phase?

    <p>G2 phase</p> Signup and view all the answers

    What is the term for the process of DNA replication where one of the two strands of each new DNA molecule was derived from the parent molecule and the other strand was newly synthesized?

    <p>Semiconservative replication</p> Signup and view all the answers

    What is the term for the time gap that separates S phase from the previous M phase?

    <p>G1 phase</p> Signup and view all the answers

    Which enzyme is involved in replication initiation in bacteria?

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

    What is the direction of DNA replication fork movement in bacteria?

    <p>Away from the origin</p> Signup and view all the answers

    Which proteins are involved in eukaryotic replication initiation?

    <p>ORC and MCM</p> Signup and view all the answers

    What activity of DNA polymerase is responsible for proofreading during replication?

    <p>3'→ 5' exonuclease activity</p> Signup and view all the answers

    What initiates DNA replication in both prokaryotes and eukaryotes?

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

    What did Matthew Meselson and Franklin Stahl use to distinguish DNA strands in their experiment?

    <p>14N and 15N</p> Signup and view all the answers

    What did Cairns observe in relation to DNA replication?

    <p>Replication forks</p> Signup and view all the answers

    Which enzyme adds deoxynucleotides to the 3′ end of the RNA primer during DNA synthesis?

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

    What is the function of topoisomerases during DNA replication?

    <p>Creating swivel points in the DNA molecule</p> Signup and view all the answers

    What is the role of telomerase in maintaining telomeres?

    <p>Lengthening telomeres</p> Signup and view all the answers

    What is the function of DNA clamp proteins like PCNA during DNA replication in eukaryotes?

    <p>Coordinating origins of replication</p> Signup and view all the answers

    What problem do telomeres solve in eukaryotic DNA replication?

    <p>The DNA end-replication problem</p> Signup and view all the answers

    What is the role of replication factories in DNA replication?

    <p>Coordinating origins of replication</p> Signup and view all the answers

    What can lead to spontaneous mutations during DNA replication?

    <p>Mispairing of bases</p> Signup and view all the answers

    Which type of mutagens fall into two categories: chemicals and radiation?

    <p>Environmental mutagens</p> Signup and view all the answers

    What type of radiation alters DNA by triggering pyrimidine dimer formation?

    <p>Ultraviolet radiation</p> Signup and view all the answers

    Which repair mechanism involves the enzyme photolyase and is powered by visible light?

    <p>Light-dependent repair</p> Signup and view all the answers

    What repair mechanism corrects single damaged bases?

    <p>Base excision repair</p> Signup and view all the answers

    Which repair mechanism detects distortions in the DNA helix and recruits NER endonuclease?

    <p>Nucleotide excision repair</p> Signup and view all the answers

    What allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides?

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

    Which repair mechanism involves genetic exchange between DNA molecules with extensive sequence similarity?

    <p>Homologous recombination</p> Signup and view all the answers

    What repair mechanism involves joining broken DNA fragments without ensuring the correct DNA fragments are joined?

    <p>Nonhomologous end-joining</p> Signup and view all the answers

    Which type of mutation-causing agents can induce mutation by mobile genetic elements such as viruses or transposable elements?

    <p>Mutation-causing agents</p> Signup and view all the answers

    During which phase does DNA synthesis occur?

    <p>S phase</p> Signup and view all the answers

    What is the term for the chromosomes that have duplicated and consist of two sister chromatids?

    <p>Homologous chromosomes</p> Signup and view all the answers

    What is the division process involving nuclear division and division of the cytoplasm known as?

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

    What is the term for the gap that separates S phase from the next M phase?

    <p>G2 phase</p> Signup and view all the answers

    What is the term for the process of DNA replication where one of the two strands of each new DNA molecule was derived from the parent molecule and the other strand was newly synthesized?

    <p>Semiconservative replication</p> Signup and view all the answers

    What is the function of topoisomerases during DNA replication?

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

    What allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides?

    <p>Methylation of the parental strand</p> Signup and view all the answers

    What is the term for the sites at which eukaryotic DNA replication initiates?

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

    Which enzyme is responsible for adding RNA primers to the 3' end of an existing nucleotide chain during DNA replication?

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

    What is the term for the process where DNA polymerases catalyze elongation in the 5' to 3' direction, and DNA is synthesized in discontinuous fragments?

    <p>Okazaki fragments</p> Signup and view all the answers

    What is the name of the complex involved in eukaryotic replication initiation?

    <p>Origin recognition complex (ORC)</p> Signup and view all the answers

    Which activity of DNA polymerase is responsible for proofreading during DNA replication?

    <p>3'→ 5' exonuclease activity</p> Signup and view all the answers

    What is the name of the process where certain replicons replicate early during S phase, while others replicate later?

    <p>Replication timing</p> Signup and view all the answers

    What is the term for the process where replication forks move away from the origin, unwind the DNA, and copy both strands in bacteria?

    <p>Bidirectional replication</p> Signup and view all the answers

    Which enzyme is responsible for adding deoxynucleotides to the 3′ end of the RNA primer during DNA synthesis?

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

    What is the function of telomerase in maintaining telomeres?

    <p>It protects telomeres from degradation</p> Signup and view all the answers

    What is the role of topoisomerases during DNA replication?

    <p>Preventing excessive supercoiling</p> Signup and view all the answers

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

    <p>Facilitating unwinding of the DNA double helix</p> Signup and view all the answers

    What is the purpose of replication factories in DNA replication?

    <p>Coordinating origins of replication</p> Signup and view all the answers

    What is the function of chromatin remodeling proteins during DNA replication?

    <p>Loosening nucleosome packing</p> Signup and view all the answers

    What is the main role of telomeres in solving the DNA end-replication problem in eukaryotes?

    <p>Maintaining chromosome integrity</p> Signup and view all the answers

    Which type of mutagens is known to cause DNA damage by triggering pyrimidine dimer formation?

    <p>Radiation mutagens</p> Signup and view all the answers

    What repair mechanism involves the enzyme photolyase and is powered by visible light?

    <p>Light-dependent repair</p> Signup and view all the answers

    Which repair mechanism detects distortions in the DNA helix and recruits NER endonuclease?

    <p>Nucleotide excision repair</p> Signup and view all the answers

    What type of radiation removes electrons from molecules and generates highly reactive intermediates that damage DNA?

    <p>Ionizing radiation</p> Signup and view all the answers

    Which repair mechanism is error-prone and involves joining broken DNA fragments without ensuring the correct DNA fragments are joined?

    <p>Nonhomologous end-joining</p> Signup and view all the answers

    What allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides?

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

    Which repair mechanism corrects single damaged bases?

    <p>Base excision repair</p> Signup and view all the answers

    What is the process called when abnormal nucleotides are removed and replaced after DNA replication?

    <p>Excision repair</p> Signup and view all the answers

    Which repair mechanism involves genetic exchange between DNA molecules with extensive sequence similarity?

    <p>Homologous recombination</p> Signup and view all the answers

    What is the term for the process where DNA polymerases catalyze elongation in the 5' to 3' direction, and DNA is synthesized in discontinuous fragments?

    <p>Replication factory synthesis</p> Signup and view all the answers

    What is the name of the complex involved in eukaryotic replication initiation?

    <p>Origin recognition complex</p> Signup and view all the answers

    What is the function of topoisomerases during DNA replication?

    <p>Unwinding the DNA double helix</p> Signup and view all the answers

    During which phase does DNA synthesis occur?

    <p>S phase</p> Signup and view all the answers

    What is the term for the gap that separates S phase from the next M phase?

    <p>G2 phase</p> Signup and view all the answers

    What is the purpose of replication factories in DNA replication?

    <p>To organize and coordinate DNA synthesis</p> Signup and view all the answers

    What is the term for the chromosomes that have duplicated and consist of two sister chromatids?

    <p>Replicated chromosomes</p> Signup and view all the answers

    Which enzyme is responsible for adding deoxynucleotides to the 3′ end of the RNA primer during DNA synthesis?

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

    What is the main role of telomeres in solving the DNA end-replication problem in eukaryotes?

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

    What is the function of topoisomerases during DNA replication?

    <p>Preventing excessive supercoiling</p> Signup and view all the answers

    What is the term for the highly repeated sequences at chromosome ends that solve the DNA end-replication problem in eukaryotes?

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

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

    <p>Unwinding the DNA double helix</p> Signup and view all the answers

    What is the term for the process of lengthening telomeres by adding repetitive sequences?

    <p>Telomere elongation</p> Signup and view all the answers

    What is the term for the coordinated process on both leading and lagging strands during DNA replication?

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

    What did Matthew Meselson and Franklin Stahl use to distinguish DNA strands in their experiment?

    <p>14N and 15N isotopes</p> Signup and view all the answers

    Which repair mechanism involves genetic exchange between DNA molecules with extensive sequence similarity?

    <p>Homologous recombination</p> Signup and view all the answers

    What is the term for the process where replication forks move away from the origin, unwind the DNA, and copy both strands in bacteria?

    <p>Bidirectional replication</p> Signup and view all the answers

    Which enzyme is involved in replication initiation in bacteria?

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

    What is the function of DNA clamp proteins like PCNA during DNA replication in eukaryotes?

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

    What is the term for the chromosomes that have duplicated and consist of two sister chromatids?

    <p>Replicated chromosomes</p> Signup and view all the answers

    What is the main role of telomeres in solving the DNA end-replication problem in eukaryotes?

    <p>Prevent loss of genetic material</p> Signup and view all the answers

    Which repair mechanism involves the enzyme photolyase and is powered by visible light?

    <p>Nucleotide excision repair</p> Signup and view all the answers

    What type of radiation alters DNA by triggering pyrimidine dimer formation?

    <p>Ultraviolet radiation</p> Signup and view all the answers

    What allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides?

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

    Which repair mechanism corrects single damaged bases?

    <p>Base excision repair</p> Signup and view all the answers

    What is the term for the process where DNA polymerases catalyze elongation in the 5' to 3' direction, and DNA is synthesized in discontinuous fragments?

    <p>Lagging strand synthesis</p> Signup and view all the answers

    Which repair mechanism is error-prone and involves joining broken DNA fragments without ensuring the correct DNA fragments are joined?

    <p>Double-strand break repair</p> Signup and view all the answers

    What initiates DNA replication in both prokaryotes and eukaryotes?

    <p>Origin of replication</p> Signup and view all the answers

    Which repair mechanism involves genetic exchange between DNA molecules with extensive sequence similarity?

    <p>Homologous recombination</p> Signup and view all the answers

    Which repair mechanism involves joining broken DNA fragments without ensuring the correct DNA fragments are joined?

    <p>Nonhomologous end-joining</p> Signup and view all the answers

    Study Notes

    Mutagens, DNA Damage, and Repair Mechanisms

    • DNA damage can be caused by mutation-causing agents, mutagens
    • Environmental mutagens fall into two categories: chemicals and radiation
    • Mutation can also be induced by mobile genetic elements, such as found in viruses, or transposable elements (transposons)
    • Base analogues, base-modifying agents, and intercalating agents are types of chemical mutagens
    • Ultraviolet radiation alters DNA by triggering pyrimidine dimer formation
    • X-rays and related types of radiation, called ionizing radiation, remove electrons from molecules and generate highly reactive intermediates that damage DNA
    • Light-dependent repair involves the enzyme photolyase and is powered by visible light
    • Base excision repair corrects single damaged bases, while nucleotide excision repair detects distortions in the DNA helix and recruits NER endonuclease
    • Errors remaining after DNA replication are repaired by excision repair, in which abnormal nucleotides are removed and replaced
    • DNA methylation allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides
    • Double-strand breaks cleave DNA into two fragments, and are repaired using nonhomologous end-joining and homologous recombination
    • Nonhomologous end-joining is error-prone and involves joining broken DNA fragments without ensuring the correct DNA fragments are joined, while homologous recombination involves genetic exchange between DNA molecules with extensive sequence similarity

    Mutagens, DNA Damage, and Repair Mechanisms

    • DNA damage can be caused by mutation-causing agents, mutagens
    • Environmental mutagens fall into two categories: chemicals and radiation
    • Mutation can also be induced by mobile genetic elements, such as found in viruses, or transposable elements (transposons)
    • Base analogues, base-modifying agents, and intercalating agents are types of chemical mutagens
    • Ultraviolet radiation alters DNA by triggering pyrimidine dimer formation
    • X-rays and related types of radiation, called ionizing radiation, remove electrons from molecules and generate highly reactive intermediates that damage DNA
    • Light-dependent repair involves the enzyme photolyase and is powered by visible light
    • Base excision repair corrects single damaged bases, while nucleotide excision repair detects distortions in the DNA helix and recruits NER endonuclease
    • Errors remaining after DNA replication are repaired by excision repair, in which abnormal nucleotides are removed and replaced
    • DNA methylation allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides
    • Double-strand breaks cleave DNA into two fragments, and are repaired using nonhomologous end-joining and homologous recombination
    • Nonhomologous end-joining is error-prone and involves joining broken DNA fragments without ensuring the correct DNA fragments are joined, while homologous recombination involves genetic exchange between DNA molecules with extensive sequence similarity

    Mutagens, DNA Damage, and Repair Mechanisms

    • DNA damage can be caused by mutation-causing agents, mutagens
    • Environmental mutagens fall into two categories: chemicals and radiation
    • Mutation can also be induced by mobile genetic elements, such as found in viruses, or transposable elements (transposons)
    • Base analogues, base-modifying agents, and intercalating agents are types of chemical mutagens
    • Ultraviolet radiation alters DNA by triggering pyrimidine dimer formation
    • X-rays and related types of radiation, called ionizing radiation, remove electrons from molecules and generate highly reactive intermediates that damage DNA
    • Light-dependent repair involves the enzyme photolyase and is powered by visible light
    • Base excision repair corrects single damaged bases, while nucleotide excision repair detects distortions in the DNA helix and recruits NER endonuclease
    • Errors remaining after DNA replication are repaired by excision repair, in which abnormal nucleotides are removed and replaced
    • DNA methylation allows mismatch repair systems to distinguish the original DNA from the newly made strand and replace incorrect nucleotides
    • Double-strand breaks cleave DNA into two fragments, and are repaired using nonhomologous end-joining and homologous recombination
    • Nonhomologous end-joining is error-prone and involves joining broken DNA fragments without ensuring the correct DNA fragments are joined, while homologous recombination involves genetic exchange between DNA molecules with extensive sequence similarity

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    11_17_lecture.pptx

    Description

    Test your knowledge of mutagens, DNA damage, and repair mechanisms with this quiz. Explore the different types of mutation-causing agents, environmental mutagens, and the various repair mechanisms that cells employ to maintain genomic integrity.

    More Like This

    DNA Damage and Repair Quiz
    5 questions

    DNA Damage and Repair Quiz

    RejoicingLaboradite avatar
    RejoicingLaboradite
    DNA Damage and Repair Quiz
    5 questions

    DNA Damage and Repair Quiz

    HonoredCommonsense1813 avatar
    HonoredCommonsense1813
    Induced DNA Damage and Mutagens
    32 questions
    Use Quizgecko on...
    Browser
    Browser