Bio 30

• Definition of Genetics:

  • Branch of Biology that studies heredity and variation
  • Heredity: transmission of traits from parents to offspring, similarity of parents and offspring
  • Variation: differences between parents and offspring, differences among offspring, differences among individuals in the population
• • From the color of your hair, eyes, and skin, face shape, to all your skills and the way you laugh - everything's a combination of genetics

  3. Population genetics:

  • Studies the genetic composition of groups of individuals of the same species (population)
  • How the composition changes over time, study of evolution (genetic changes)
• Three interrelated fields in Genetics:

  1. Transmission genetics:

  • Also known as classical genetics
  • Encompasses the basic principles of genetics
  • Discusses the relationship between chromosomes and heredity
  • How the individual inherits its genetic makeup and passes it on to the next generation
  • Chromosomes as bearers of genes, arrangement of genes on chromosomes
  • Map the genes on chromosomes

  2. Molecular genetics:

  • Chemical nature of the gene
  • How genetic information is replicated, encoded, and expressed
• Branches of Genetics:

  1. Molecular Genetics:

  • Structure and functions of genes at the molecular level
  • Processes in the Central Dogma of Molecular Biology

  2. Cytogenetics:

  • Behavior of chromosomes - carrier of genes

  3. Developmental Genetics:

  • Gene regulation during development
  • Switching on and off of genes

  4. Evolutionary Genetics:

  • Genetic change within and between species

  5. Biochemical Genetics:

  • Role of enzymes and proteins, products of genes, genetic basis of metabolic disorders

  6. Behavioral Genetics:

  • Behavioral traits that are inherited, genetic basis of behavioral disorders
• 7. Population Genetics:

  • Fate of genes in the population, factors affecting gene frequencies

  8. Quantitative Genetics:

  • Inheritance and expression of quantitative traits, role of genetic and environmental factors
• • Chromosome Theory of Inheritance by Walter Sutton and Theodor Boveri
  • Discovery of DNA as hereditary material by Oswald Avery, Colin MacLeod, & Maclyn McCarty
  • Elucidation of the DNA structure in 1953 by James D. Watson and Francis H. Crick
• Beginnings of Genetics:

  • Before Gregor Mendel: heredity as blending process, offspring are intermediate between the parents, not true if offspring is similar to one of the parents
  • Golden Age of Greek Culture: attention was given to reproduction and heredity
  • Theories by Hippocrates, Aristotle, Darwin, Jean Baptiste de Lamarck, August Weismann
  • Gregor Mendel: Father of Genetics, responsible for the principles of segregation and independent assortment
  • Rediscoverers of Mendel's work: Carl Correns, Erick von Tschermak, Hugo de Vries, William Bateson, Saunders, Lucien Cuenot
• Applications of Genetics:

  1. Microbial, plant, and animal improvement

  2. Medicine:

  • Identification of diseases and abnormalities with genetic basis
  • Gene therapy, human gene editing

  3. Genetic Counselling:

  • Inheritance of undesirable traits, pedigree analysis of prospective patients
  • Eugenics and Euphenics

  4. Legal Applications:

  • Blood type analysis, DNA fingerprinting for paternity testing, disputed parentage, criminal identification
• Scope of Genetics:

  • Different branches of genetics are dependent on other fields like Physical Chemistry, Biophysics, Biochemistry, Physics, Staining Technology, Ecology, Math, Statistics, Physiology, Morpho-anatomy, Psychology