Genetics Ch. 1

• Genetics


  The study of heredity; Study of how inherited characteristics are encoded, replicated, expressed and changed over time.
• Why study genetics

  • Genes influence susceptibility to many disorders and diseases
  • Genetic techniques were used to develop new high-yielding strains of crops
• Genome


  A complete set of genetic instructions for any organism. Either RNA or DNA. Copied during process of replication.
• Divisions of Genetics

  • Transmission genetics
  • Molecular genetics
  • Population genetics
• Transmission Genetics

  Studies how traits are passed from generation to generation. Relationship between chromosomes and heredity. Focus is on the "individual" organism.
• Molecular genetics

  Chemical nature of the gene (how it is encoded, replicated and expressed). Structure and organization.
• Population Genetics

  Genetic composition of a group of individuals within the same species and how that composition changes over time.
• Sickle cell anemia

  An inherited red blood cell disorder where there aren't enough healthy red blood cells to carry oxygen throughout your body. The red blood are shaped like sickles or crescent moons, which can get stuck in small blood vessels, slowing or blocking blood flow and oxygen to parts of the body.
• Studying humans can get COMPLICATED! We can't easily control their environments, they have few offspring, we can't control their "matings" and the genomes are HUGE!
• Common Characteristics of Model Organisms

  • Short generation time
  • Production of numerous progeny
  • The ability to carry out controlled genetic crosses
  • The ability to be studied in a laboratory environment
  • The availability of numerous genetic variants
  • An accumulated body of knowledge about their genetic systems
• Understanding of genetics of hemophilia


  Ancient Jewish writing
• Theories of inheritance

  Ancient Greeks
• Pangenesis


  Each part of the body contains genetic information for that particular part. Specific particles, called gemmules, carry information from parts of the body to the reproductive organs. Then passed to the embryo at the moment of conception. Compared with the Modern Germ-Plasm Theory
• Pangenesis is PROVEN INCORRECT
• Inheritance of acquired characteristics

  Traits acquired in a person's lifetime become incorporated into that person's hereditary information and are passed on to offspring. Jean-Baptist Lamarck.
• Inheritance of acquired characteristics is PROVEN (Mostly) INCORRECT, with the exception of epigenetics.
• Preformationism


  Inside the egg or sperm exists a fully formed miniature adult, a homunculus (TINY HUMAN), which simply enlarges in the course of development.
• Blending inheritance


  Traits of offspring are a blend, or mixture, of parental traits. After "blending" the individual traits are not recovered in future generations.
• The Rise of the Science of Genetics

  • Gregor Mendel (1866): principles of heredity
  • Schleiden and Schwann: cell theory
  • Flemming: chromosomes
  • Darwin: evolution
  • Weismann: germ-plasm theory
  • Sutton: genes located on chromosomes
  • Other modern geneticists
• Gregor Mendel


  Discovered the basic principles of heredity and laid the foundation for our modern understanding of heredity. Generally recognized today as the "father of genetics".
• Cell Theory

  All life is composed of cells, cells arise only from preexisting cells, and the cell is the fundamental unit of structure and function in living organisms. Schleiden and Schwann.
• Chromosomes


  Walther Flemming observed the division of chromosomes in 1879 and published a description of mitosis.
• Evolution

  Charles Darwin put forth the theory of evolution through natural selection, published in On the Origin of Species in 1859. Randomly acquired changes resulted in unequal reproductive success.
• Germ-plasm theory


  August Weismann proposed that cells in reproductive organs carry a complete set of genetic information that is passed to the egg and sperm.
• The History of Genetics

  • Walter Sutton (1877–1916): Genes located on chromosomes
  • Thomas Hunt Morgan (1866–1945): Discovered the first mutant fruit fly in 1910, used fruit flies to unravel transmission genetics
  • Watson, Crick, Wilkins and Franklin: Molecular structure of DNA
  • Gilbert and Sanger: DNA sequencing
  • Kary Mullins (1944-2019): PCR
  • Dounda and Charpentier: 2012 CRISPER-Cas 9
• Key to development


  gene expression
• Alleles

  Different "forms" of the same gene.
• Evolution

  Change over time.
• Model Organisms

  • Fruit fly
  • Bacteria
  • Nematode
  • Thale-cress Plant
  • House Mouse
  • Baker's Yeast
• Fruit Fly

  a model of molecular mechanisms for cancer
• Bacteria

  understanding DNA replication
• Nematode

  for development and immunity
• Thale-cress Plant

  for DNA repair and agriculture
• Baker's Yeast

  for cell cycle, apoptosis (cell death), neurode generative
• Epigenetics

  genes can be turned on or off
• Performationism PROVEN INCORRECT