| 1. Incomplete dominance (snapdragons) |
| · One gene, two alleles, three phenotypes |
| · Genotypic ratios equal phenotypic ratios |
| |
| 2. Co-dominance (sickle cell anemia) |
| · Analysis of proteins by gel electrophoresis |
| · Genotype determination from protein patterns |
| · Homozygosity versus heterozygosity |
| · Screens for heterozygosity |
| · Paternity testing |
| |
| 3. Multiple alleles (ABO blood types) |
| · Two gene hypothesis versus one gene multiple alleles |
| · Genotype determination |
| |
| 4. Multiple alleles (hypothetical birds) |
| · Multiple genes versus multiple alleles |
| · Allelic series |
| · Genotypes from phenotypic ratios |
| |
| 5. Two traits, three genes, incomplete dominance
and epistasis |
| · Breakdown of complex data |
| · Phenotypic ratios to predict number of genes and relationships
between genes |
| |
| 6. Epistasis (Bombay phenotype, humans) |
| · Genotypes |
| · Discrepancy in pedigrees |
| · Epistatic gene |
| · Southern analysis |
| |
| 7. Homozygous lethality (Curled ear in cats) |
| · Spontaneous dominant mutation |
| · Homozygous dominant never found |
| · 2:1 ratios |
| · Achondroplasia (human example) |
