Fundamentals of Genetics Mendelian Genetics figured out dominance

Fundamentals of Genetics Mendelian Genetics figured out dominance in genes, law of segregation and law of independent assortment

Gregor Mendel l The “father of genetics” l Austrian monk l conducted pea plant experiments - seven observable or phenotypic traits l developed three laws based on his observations

Is it a “trait, ” an “allele, ” or a “gene? ” l A trait is what you see ie. hair color is a trait l An allele is the forms (or variations of) the trait can take ie. blond, brown, black l A gene is the location on the DNA where the info for the proteins that tell the hair color is found.

Law of Dominance and Recessiveness TRAITS Dominant alleles Recessive alleles 3: 1 purple 3: 1 axial 3: 1 yellow 3: 1 round 4: 1 inflated 4: 1 green 4: 1 tall

Law of Segregation l The two homologous chromosomes separate during anaphase I of meiosis. l The sister chromatids are separated during anaphase II of meiosis.

Law of Independent Assortment l Alleles randomly separate during meiosis. l. Homologous chromosomes line up during metaphase I without influence of other chromosomes

Mendel’s Generations l P generation is the parental generation l F = filial l F 1 generation is the offspring/progeny of a parental generation cross l F 2 generation is the offspring/progeny of an F 1 generation cross