• Genotype vs Phenotype: Genotype refers to genetic makeup, while phenotype is the observable characteristics.
• Genes: Made up of DNA and determine traits, transferred from parent to offspring
• Alleles: Different forms of the same gene, dominant allele appears, recessive allele needs two copies to be expressed
• Dominant vs Recessive Genotypes: Homozygous dominant, heterozygous, and homozygous recessive examples
• Example of Alleles and Traits: Hair color (HH, Hh, hh), Eye color (BB, Bb, bb)

Understanding dominant and recessive traits helps us understand how genotypes affect phenotypes, important in biology, genetics, and medicine.