Genetics

Simple, discrete traits

Self-pollination, cross-pollination

True breeding Monohybrid cross P generation F1 generation F2 generation

Laid the idea of blending to rest Applied mathematics to results Got the same ratio each time, regardless of the trait

Law of Segregation Each parent had two separate copies of the factor Dominant vs recessive factors Factors separated when gametes were formed Random fertilization = random fusion of all possible gametes

Locus Allele Dominant vs recessive Homozygous Heterozygous Genotype Phenotype Testcross Punnett squares Pedigrees

Dihybrid Cross Law of independent assortment: Each pair of alleles segregates independently of the other pairs All possible combinations of factors can occur in the gametes Assumption: genes are on different chromosomes

What screws this up? Crossing over Linked genes

It ain’t that simple…

Incomplete Dominance https://ghr.nlm.nih.gov/condition/hypercholesterolemia

Sex linked traits

Codominance

Multiple Alleles

Incomplete Penetrance

Pleiotropy Abnormal connective tissue

Polygenic Inheritance

Chromosomal Changes Nondisjunction: trisomy 21 (Down Syndrome) and Klinefelter’s Point mutations: sickle cell anemia Chromosomal mutations: Cri du chat, Williams

Nonnuclear inheritance Chloroplasts and mitochondria carry own DNA Transmitted from mom to kids

Environmental Effects

AP Standard The student is able to construct a representation that connects the process of meiosis to the passage of traits from parents to offspring The student is able to apply mathematical routines to determine Mendelian patterns of inheritance provided by data sets