DNA Structure and Cell Division
13 Questions
1 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

What is the correct pairing of nucleotides in DNA?

  • Cytosine pairs with Thymine
  • Adenine pairs with Cytosine
  • Guanine pairs with Thymine
  • Adenine pairs with Thymine (correct)
  • Which process results in the formation of gametes?

  • Cell differentiation
  • DNA replication
  • Mitosis
  • Meiosis (correct)
  • What year did Frederick Sanger develop DNA sequencing?

  • 1984
  • 1952
  • 1965
  • 1977 (correct)
  • Which of the following components is NOT found in DNA?

    <p>Ribonucleic Acid</p> Signup and view all the answers

    What potential consequences can result from failures in DNA replication?

    <p>Death or disease</p> Signup and view all the answers

    What is the first step in utilizing genetic genealogy for investigations?

    <p>Profile into CODIS</p> Signup and view all the answers

    Which of the following is NOT a type of index held in CODIS?

    <p>Unidentified Victim</p> Signup and view all the answers

    What process follows if there is no hit found in CODIS?

    <p>Profile into GEDmatch/FTDNA/DNAJustice</p> Signup and view all the answers

    In DNA segment triangulation, what is required for three individuals to have a common ancestor?

    <p>They must match each other on the same segment</p> Signup and view all the answers

    What is the estimated time to solve a case involving a match of 900 cM?

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

    Which step involves determining how different family trees fit together?

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

    In the Niskayuna case, what technology was used to help identify Stephen Smerk?

    <p>Composite imaging from DNA</p> Signup and view all the answers

    How many offender profiles are currently in the CODIS database?

    <p>14,492,991</p> Signup and view all the answers

    Study Notes

    The Structure and Definition of DNA

    • DNA (Deoxyribonucleic Acid) is a double helix, identified in 1953 by Francis Crick and James Watson, with contributions from Rosalind Franklin and Maurice Wilkins.
    • Rosalind Franklin's Photo 51 in 1952 played a crucial role in revealing DNA's structure.
    • DNA consists of nucleotides that include adenine (A), thymine (T), guanine (G), and cytosine (C), forming the genetic blueprint of all living cells.
    • Nucleotides pair specifically: A with T and G with C, stabilization is aided by Van der Waals forces.
    • DNA's helical structure protects its information, with sequences forming genes.

    Chromosomes and Cell Division

    • DNA is organized into chromosomes; human karyotypes contain 22 pairs of autosomes and one pair of sex chromosomes.
    • Accurate DNA replication is essential for cell division; errors can result in death, disease, or cancer.
    • Mitosis creates identical daughter cells for growth and repair, while meiosis generates gametes (sperm and egg) through division into four cells.

    DNA in Law Enforcement

    • DNA fingerprinting was pioneered by Sir Alec Jeffreys in 1984, initially utilized in a 1985 immigration case.
    • The CODIS (Combined DNA Index System) tracks profiles of convicted offenders, arrestees, and missing persons.

    STRs vs. SNPs

    • Short Tandem Repeats (STRs) are analyzed in CODIS, while Single Nucleotide Polymorphisms (SNPs) are used in Direct-to-Consumer (DTC) databases for genetic genealogy.
    • Both involve DNA extraction but differ in analysis and application, with genetic genealogy expanding upon initial CODIS findings.

    Steps in Genetic Genealogy

    • Four main steps include:
      • Find: Identify the best DNA matches.
      • Create: Construct family trees for these matches.
      • Group: Figure out how the trees are interconnected.
      • ID: Integrate your DNA into the established trees.

    DNA Segment Triangulation

    • Triangulation occurs when three individuals match on the same DNA segment, indicating they share a common ancestor.
    • This technique is vital for tracing the lineage, particularly for adoptees seeking birth parents.

    Case Studies in Genetic Genealogy

    • The Niskayuna arrest of Stephen Smerk involved forensic DNA technology that led to his identification in the cold case of Robin Lawrence's murder.
    • The NorCal Rapist case was solved swiftly through a close DNA match within 45 minutes, showcasing the efficiency of modern genetic techniques.

    Estimated Time to Solve Cases by cM Matches

    • Approximate time to solve cases varies with centiMorgans (cM):
      • 3500 cM indicates a parent (solving takes hours).
      • 2500 cM signifies a sibling.
      • 900 cM points to a 1st cousin (days to weeks).

    Studying That Suits You

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

    Quiz Team

    Description

    Explore the essential concepts of DNA structure, including its double helix formation and nucleotide pairing, as well as its organization into chromosomes. Understand the processes of mitosis and meiosis, which are vital for growth and reproduction in living organisms.

    More Like This

    Genetics: DNA and Cell Division
    63 questions

    Genetics: DNA and Cell Division

    PoeticIntelligence4099 avatar
    PoeticIntelligence4099
    Genetics and Cell Division Overview
    24 questions
    Use Quizgecko on...
    Browser
    Browser