| A | B |
|---|
| Pedigree Studies | a family record showing how a trait is inherited over several gernerations |
| Codominant Trait | Both alleles or traits are expressed (Ex.BW=checkered chicken) |
| Sickle Cell Disease | Codominant trait- HAHS gives protection from Malaria, HSHS- gives sickle cell anemia |
| Multiple Alleles | Controlled by more than 2 alleles (Ex. blood types) |
| Blood Types | A (IAIA or IAi),B(IBIB or IBi),AB(IAIB),O(ii) |
| Polygenic | Traits that are controlled by several GENES (Ex.height) |
| Autosomes | all chromosomes except sex chromosomes |
| Sex-linked | Trait is found on the X or Y chromosome (Ex.Hemophilia/colorblindeness) |
| Sex Influenced Traits | not carried on the X chromosome but gender influences expression (Ex.baldness) |
| XX | Female |
| XY | Male |
| Incomplete Dominance | Neither trait is dominant (Ex. RR' or RW =Pink snapdragons) |
| Nettie Stevens | Discovered sex chromosomes |
| Beadle and Tatum | Determined "one gene=one enzyme (protein)" |
| Thomas Hunt Morgan | Used fruit flies to determine genes are on chromosomes |
| Walter Sutton | Determined traits are carried on chromosomes (Chromosomal Theory of Inheritance) |
| Barbara McClintock | Determined genes are transposable "jumping genes" |
| Gregor Mendel | Father of Genetics, Formulated 3 Laws of Heredity |
| In incomplete dominance, the hybrids show... | blending |
| Hybrid | Mixed alleles-heterozygous (Ss) |
| Purebred | Same alleles-homozygous (SS or ss) |
| Nondisjunction | The failure of homologous chromosomes to separate in meiosis (causes Down's syndrome) |
| Karyotype | Picture of chromosomes used to determine genetic disorders |
| gene | segment of DNA that codes for a trait |
