DNA replication

• What is the theme associated with DNA replication in the study material?

  Continuity and Change
• What is the level of organization discussed in the context of DNA replication?

  Molecules
• What are the IB guiding questions related to DNA replication?

  How is new DNA produced? How has knowledge of DNA replication enabled applications in biotechnology?
• What are the key terms associated with DNA replication?

  • DNA
  • Nucleotide
  • DNA Replication
  • Helicase
  • DNA Polymerase
  • Complementary Base Pairs
  • Semi-Conservative
  • Polymerase Chain Reaction (PCR)
  • Primers
  • Taq DNA Polymerase
  • Denaturation
  • Annealing
  • Gel Electrophoresis
  • DNA Profile
  • Restriction Endonuclease
  • DNA Markers
• What does DNA stand for?

  Deoxyribonucleic acid
• Why is DNA replication necessary for multicellular organisms?

  It is required for reproduction and for growth and tissue replacement.
• What is the definition of DNA replication?

  DNA replication is the production of identical copies of DNA.
• What is the significance of the semi-conservative nature of DNA replication?

  New DNA molecules have one parent strand and one newly synthesized strand.
• What roles do helicase and DNA polymerase play in DNA replication?

  Helicase unwinds the DNA double helix, while DNA polymerase links nucleotides to form a new strand.
• How does helicase function during DNA replication?

  Helicase unwinds the DNA double helix by breaking the hydrogen bonds between complementary nucleotides.
• What are the complementary base pairs in DNA?

  Adenine pairs with Thymine, and Guanine pairs with Cytosine.
• What is the result of DNA replication?

  Two identical strands of DNA are produced.
• What is the purpose of primers in the polymerase chain reaction (PCR)?

  Primers attach to the DNA to be copied.
• What is Taq DNA polymerase and why is it used in PCR?

  Taq DNA polymerase is obtained from a bacterium and is not denatured at high temperatures.
• What are the steps involved in the polymerase chain reaction (PCR)?

  Denaturation, Annealing, and Extension.
• What happens during the denaturation step of PCR?

  The DNA sample is heated to 95°C to break hydrogen bonds and separate the two DNA strands.
• What occurs during the annealing step of PCR?

  The temperature is reduced to 54°C, allowing DNA primers to bind to both strands of DNA.
• What is the role of Taq DNA polymerase during the extension step of PCR?

  Taq DNA polymerase replicates both strands, starting at the primer.
• What is gel electrophoresis used for?

  Gel electrophoresis is used to separate charged molecules like DNA or proteins.
• How does gel electrophoresis produce a DNA profile?

  A DNA profile is created from an individual's DNA fragments using gel electrophoresis.
• What is the significance of restriction endonuclease in DNA profiling?

  Restriction endonuclease enzymes cut DNA into many negatively charged fragments.
• How do DNA fragments behave in gel electrophoresis?

  DNA fragments move from the negative electrode to the positive electrode.
• What is the relationship between the size of DNA fragments and their movement in gel electrophoresis?

  Smaller (lighter) fragments move faster than larger (heavier) fragments.
• What is the process of creating a DNA profile using gel electrophoresis?

  A DNA sample is amplified using PCR, cut into fragments, and then separated in agar gel using electricity.
• How can DNA profiles be used in forensic investigations?

  DNA from crime scenes can be processed to produce a DNA profile for comparison with suspects.
• How can DNA profiles assist in paternity testing?

  A child's DNA profile will match either the mother or father, allowing determination of paternity.
• What must happen for a suspect to be identified using DNA profiles?

  All bands on a DNA profile of a suspect must match the profile from a crime scene.
• What is the importance of increasing the number of markers in DNA profiling?

  Increasing the number of markers reduces the probability of a false match.
• Why is it important for DNA profiles to produce reliable results?

  Reliable results are crucial to correctly match suspects with a crime and avoid false matches.
• What is produced to create a DNA profile?

  A DNA profile is produced from processed DNA.
• How can a crime scene DNA profile be used?

  It can be compared to DNA profiles from individuals suspected of committing the crime.
• What does paternity testing reveal about a child and its parents?

  A child shares half of its DNA with each parent.
• How can DNA profiles determine if a man is a child's father?

  The child's DNA profile bands will match either the mother or father.
• What online activity can help solve the mystery of who stole Jimmy's lollipop?

  Completing the online activity to identify the person who stole Jimmy's lollipop.
• What must match to identify a suspect from a crime scene DNA profile?

  All bands on the DNA profile of a suspect must match the crime scene profile.
• Who was identified as being at the crime scene in the DNA profiles?

  Suspect 2 was at the crime scene.
• How can DNA profiles be used in paternity testing?

  They can determine if the bands in the child's profile appear in the mother's or father's profile.
• What is crucial for the reliability of DNA profiles in criminal investigations?

  DNA profiles must produce reliable results and not provide a false match.
• What are DNA markers?

  DNA markers are sections of DNA used to create a DNA profile.
• How can scientists increase the reliability of DNA profiles?

  By increasing the number of DNA markers used.