Non-Medellin Inheritance Part 2 (Hard)
24 Questions
2 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 primary reason for the destruction of paternal mitochondria after fertilization?

  • Paternal mitochondria are larger than maternal mitochondria
  • Paternal mitochondria have a different DNA structure
  • Paternal mitochondria are unable to replicate
  • Paternal mitochondria are modified by ubiquitin, a small regulatory protein (correct)

    • What is the characteristic of human mitochondrial diseases?

  • They are caused by environmental factors
  • They are inherited from the father
  • They are acute and affect all cells
  • They are chronic and affect cells requiring high levels of ATP (correct)

    • What is the consequence of mitochondrial mutations in somatic cells?

  • They are eliminated from the cell
  • They are immediately repaired by mitochondrial DNA repair mechanisms
  • They accumulate as a person ages (correct)
  • They have no effect on the cell

    • What is the pattern of transmission of human mitochondrial diseases?

    <p>Strict maternal inheritance</p> Signup and view all the answers

    What is the significance of heteroplasmy in mitochondrial disease?

    <p>It can lead to varying symptoms within a given family</p> Signup and view all the answers

    What is the mitochondrial gene mutated in Leber hereditary optic neuropathy?

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

    What is the consequence of a high ratio of mutant to normal mitochondria in a cell?

    <p>The cell may exceed a threshold value and express disease</p> Signup and view all the answers

    What is the goal of the three-parent baby technology?

    <p>To reduce the risk of mitochondrial disease transmission</p> Signup and view all the answers

    What is the effect of high oxygen consumption on mitochondrial DNA?

    <p>It leads to DNA damage and free radical formation</p> Signup and view all the answers

    What is the significance of ubiquitin in the destruction of paternal mitochondria?

    <p>It targets paternal mitochondria for destruction</p> Signup and view all the answers

    What is the primary function of mitochondria?

    <p>Oxidative phosphorylation</p> Signup and view all the answers

    How many base pairs are present in the human mitochondrial DNA?

    <p>17,000 bp</p> Signup and view all the answers

    What is the primary source of mitochondrial proteins?

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

    What is the range of variation in the size of mitochondrial genomes?

    <p>400-fold</p> Signup and view all the answers

    What is the primary function of the 13 polypeptides encoded by mitochondrial DNA?

    <p>Oxidative phosphorylation</p> Signup and view all the answers

    What is the size of mitochondrial genomes in plants?

    <p>Fairly large</p> Signup and view all the answers

    What is the main reason for maternal inheritance of mitochondria in animals?

    <p>Destruction of Sperm Mitochondrial DNA Prior to Fertilization</p> Signup and view all the answers

    Which of the following organisms exhibits paternal inheritance of mitochondria and chloroplasts?

    <p>Gymnosperms (Plants)</p> Signup and view all the answers

    What is the primary mechanism of maternal inheritance in Drosophila?

    <p>Destruction of Sperm Mitochondrial DNA Prior to Fertilization</p> Signup and view all the answers

    In which type of plants is biparental inheritance of mitochondria and chloroplasts observed?

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

    What is the primary reason for maternal inheritance of mitochondria in mammals?

    <p>Lack of Entry of Sperm Mitochondria</p> Signup and view all the answers

    Which of the following is NOT a mechanism of maternal inheritance of mitochondria in animals?

    <p>Biparental Inheritance</p> Signup and view all the answers

    Which species exhibits lack of entry of sperm mitochondria as a mechanism of maternal inheritance?

    <p>Chinese hamsters (Cricetulus griseus)</p> Signup and view all the answers

    What is responsible for destroying mitochondrial DNA in sperm during maturation in Drosophila?

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

    Study Notes

    Destruction of Sperm Mitochondria After Fertilization

    • Paternal mitochondria that enter the egg are modified by ubiquitin, a small regulatory protein that targets organelle destruction
    • This process occurs in most mammals, including humans

    Maternal Inheritance of Mitochondria

    • Human mtDNA is transmitted from the female parent to offspring via the cytoplasm of the egg
    • Therefore, the transmission of human mitochondrial diseases follows a strict maternal inheritance pattern

    Human Mitochondrial Diseases

    • Over 200 human mitochondrial diseases have been identified
    • These diseases are typically chronic degenerative disorders affecting cells requiring high levels of ATP, such as nerve and muscle cells
    • Examples of human mitochondrial diseases include:
      • Leber hereditary optic neuropathy, caused by mutations in mitochondrial genes encoding respiratory chain proteins
      • Neurogenic muscle weakness, caused by mutations in the ATPase6 gene
      • Mitochondrial myopathy and maternal myopathy and cardiomyopathy, caused by mutations in genes encoding tRNA for leucine

    Heteroplasmy in Mitochondrial Disease

    • Heteroplasmy is an important factor in mitochondrial disease, where cells can contain a mixed population of mitochondria, some with disease-causing mutations and others without
    • The ratio of mutant to normal mitochondria can exceed a threshold value, leading to disease symptoms that may vary widely within a given family

    Three Parent Babies

    • A new reproductive technology has emerged to prevent the transmission of mitochondrial diseases from mothers to their offspring
    • This technology was pioneered by John Zhang and colleagues in 2016, and involves replacing the mother's mitochondria with those from a donor woman

    Mechanisms of Maternal Inheritance

    • There are three mechanisms responsible for maternal inheritance of mitochondria:
      • Lack of entry of sperm mitochondria into the egg
      • Destruction of sperm mitochondrial DNA prior to fertilization
      • Destruction of sperm mitochondria after fertilization

    Sizes of Organellar Genomes

    • The sizes of organellar genomes vary greatly among different species, with a 400-fold variation in the size of mitochondrial genomes
    • Mitochondrial genomes are fairly small in animals, intermediate in size in fungi and protists, and fairly large in plants

    Mitochondrial DNA

    • The main function of mitochondria is oxidative phosphorylation, which generates ATP (adenosine triphosphate) for cellular reactions
    • Human mitochondrial DNA (mtDNA) consists of only 17,000 bp and includes genes for rRNA, tRNA, and 13 polypeptides involved in oxidative phosphorylation
    • Most mitochondrial proteins are encoded by genes in the nucleus and are made in the cytoplasm before being transported into the mitochondria

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Non-Mendelian Inheritance Part II Lecture PDF

    Description

    Learn about the destruction of sperm mitochondria after fertilization and the maternal inheritance of mitochondria in humans, including the transmission of mitochondrial diseases.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser