1. Gregor Mendel Book: “Experiments in Plant Hybridization”

2. Why Mendel was successful… He studied single traits He used LARGE sample sizes Introduced Ratios

3. Terms to KNOW Allele: 1 of 2 or more different forms of a gene. Represented as a letter. 2 alleles make a genotype. Genotype: Genetic Make-up represented as 2 alleles, one from each parent. Ex: “AA, Aa, aa” Phenotype: Physical Characteristic. Ex: Blue eyes. Dominant: Allele that will be expressed. Represented as a capital letter. Ex: “A” Recessive: Allele that is “hidden.” Represented as a lower case letter. Ex: “a” Homozygous: 2 of the same alleles Example: AA or aa Heterozygous: 2 different alleles Example: Aa

4. MORE Terms to Know Monohybrid: Individual that is heterozygous for one trait. Ex: Aa Monohybrid Cross: Genetic Cross between 2 heterozygotes. Ex: Aa x Aa First and Second Parental Generations P 1 and P 2 First and Second Filial Generations (offspring- filial means child in Latin) F 1 and F 2

5. Law of Dominance : If a dominant allele is present, the dominant phenotype will be expressed. ModelGenotype symbol Genotype description PhenotypeType of organism that exhibits genotype RRHomozygous Dominant RoundPure bred rrHomozygous recessive WrinkledPure bred RrHeterozygousRoundHybrid

6. Law of Segregation During the formation of gametes (in meiosis), alleles of gametes separate (segregate). Each G allele has separated from the other.

7. Punnett Square Diagram showing the possible combinations of offspring from a genetic cross rr RRr R Parents Offspring

8. Rr RRRRr r rr rr RRr R Pisum sativum Pea Plants P1= round (RR) x wrinkled (rr) F1 = round (Rr) P2= round (Rr) x round (Rr) F2 = 5,474 round, 1,750 wrinkled

9. Types of Ratios 1. Genotypic Homozygous Dominant : Heterozygous: Homozygous Recessive 2. Phenotypic Dominant : Recessive Example: genotypic ratio ________ ; phenotypic ratio _______ RR Rr R R r R 2:2:0 or 1:1:0 4:0 or 1:0

10. Monohybrid Cross Ratios RRRr rr R R r r 1:2:1 Genotypic Ratio: Phenotypic Ratio: 3:1