Understanding Gene Expression and Phenotypes

Oct 19, 2024

Lecture Notes: Gene Expression and Phenotypes

Overview of DNA and Genetic Information

  • Structure of DNA
    • DNA structure and how it's copied
    • Transmission of genetic information across generations
  • Protein Synthesis
    • DNA used to build proteins in cells
  • Genetic Variability
    • Accumulation of changes in DNA over time
    • Mechanisms causing these changes
    • DNA sharing in bacteria

Gene Expression Control

  • Definition: Conversion of DNA information into proteins
  • Operon: Structure in bacterial DNA controlling gene expression
    • Contains genes for necessary proteins
    • Includes regulatory sequences to control gene expression
  • Gene Clusters
    • Related proteins in a pathway often clustered in bacteria

Genotype and Phenotype

  • Genotype
    • Complete sequence of DNA inherited from parents
    • All the genes (from mother and father)
  • Phenotype
    • Observable traits and physical appearance
    • Result of protein expression

Examples of Phenotype

  • Sickle Cell Anemia
    • Individuals produce both normal and sickle cell hemoglobin
  • Human Characteristics
    • Differences in height, hair color, and patterns
    • Despite 99.9% genetic similarity, differences exist
  • Genotype vs. Phenotype
    • Unique genes (genotype) and their expression (phenotype)
    • Example: Tall vs. short individuals
  • Phenotypic Traits
    • Traits determined by gene expression and environmental influence

Environmental Influence on Phenotype

  • Genetics and Environment
    • Phenotype affected by both DNA and environmental factors
  • Example: Korean Peninsula
    • Similar genetic makeup between North and South Koreans
    • Differences due to political systems affecting nutrition
    • Height differences attributed to available nutrition
  • Global Perspective
    • Stunted growth in children due to malnutrition
    • Examples from sub-Saharan Africa, South Asia, and more

Conclusion

  • Gene Expression and Phenotype
    • Genotype influences phenotype but does not solely determine it
    • Environmental factors play a significant role in phenotypic traits
  • Focus
    • Upcoming focus on how gene expression controls phenotypes and the role of genes themselves.