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.