2. Background Info Gregor Mendel –Austrian Monk (1822-1884) –Father of Genetics –Genetics – study of heredity –Heredity – passing of characteristics from parent to offspring.

3. Background Info Gregor Mendel –Identified that all traits are controlled by a “factor” –This “factor” is a gene –GENE – section of a chromosome/DNA that codes for a trait. –TRAIT– characteristic passed from parent to offspring

4. Genome ALL of an organism’s genetic material

5. Background Info Gregor Mendel Studied Pea Plants to show how traits are passed from one generation to the next He applied math to his observations Studied pea plants because they came in 2 distinct forms

6. Why did he choose the Pea Plant? 1. The Structure of the Pea Flower 2. The seven distinct traits (2 distinct forms) 3. Rapid reproduction ( Most pea plants reproduce in 90 days)

7. Pea Plant Traits (Each trait only has 2 distinct forms)

8. Genes & Alleles Genes – chemical factors that determine traits (Flower color) Alleles – different forms of genes that code for traits (Purple flowers or White flowers)

9. Mendel found Dominant and Recessive Traits An Allele is a distinct form of a gene A dominant allele is the form that is visibly seen. A recessive allele is the form that is there but not seen (unless there are 2 recessive alleles together).

10. Symbols Dominant Alleles –Capital Letters Recessive Alleles –Lower Case Letters

11. Genotypes Genotype –Genetic makeup represented by symbols –AA, Aa, aa, TT, Bb, dd

12. Phenotypes Phenotype –Physical appearance expressed in words –Brown hair, Green eyes, Freckles

13. Heterozygous Heterozygous (different) –Gene pairs that carry one dominant and one recessive allele –Aa, Bb, Cc, Dd

14. Homozygous Homozygous (same) –Gene pairs that carry 2 dominant OR 2 recessive alleles –AA, aa, BB, bb

15. Probability Determining the likelihood of an event to occur Can be shown in 3 ways –Fraction 1/2 –Percent 50% –Ratio 1:2

16. Hybrids & Purebreds Hybrids receive different alleles from each parent (Hh, Bb, Zz) Purebreds receive the same alleles from each parent (HH, bb, ZZ)

17. Laws of Genetics Law of Dominance: Dominant traits will always show over recessive traits Law of Segregation: Alleles separate during meiosis Law of Independent Assortment: gene pairs separate randomly and independently of each other

18. Mendel’s Crosses He started with 2 groups of purebred plants, called the P 1 generation. 1.He crossed the purebreds by hand. 2.The P 1 ’s offspring was called the F 1 generation. The F 1 s then self-fertilized. 3.The F 1 ’s offspring was known as the F 2 generation.

20. Monohybrid Crosses A genetic cross that looks at 1 trait Cross a homozygous tongue roller with a non- tongue roller Genotype of parents –TT x tt Phenotypes of parents –Tongue roller, non-tongue roller Possible Outcomes –Genotypic ratio 100%Tt –Phenotypic ratio 4 Tongue rollers:0 non-tongue rollers TT t t TtTtTtTt TtTt TtTt

21. Monohybrid Crosses Cross 2 Heterozygous tongue rollers Genotype of parents –Tt x Tt Phenotypes of parents –Tongue roller, Tongue roller Possible Outcomes –Genotypic ratio 1TT:2Tt:1tt –Phenotypic ratio 3 tongue rollers: 1 non- tongue roller Tt T t TtTtt TtTtT

22. Monohybrid Crosses Cross a heterozygous Tongue roller with a Non-Tongue roller Genotype of parents –Tt x tt Phenotypes of parents –Tongue roller, non-tongue roller Possible Outcomes –Genotypic ratio 2Tt:2tt –Phenotypic ratio 2 tongue rollers:2 non- tongue rollers Tt t t TtTtt tTtTt

23. Dihybrid Crosses A genetic cross that looks at 2 traits Cross 2 heterozygous green, round peas GgRr x GgRr Genotypic Ratio –1:2:1:2:4:2:1:2:1 Phenotypic Ratio –9:3:3:1 G= greenR= Round g = yellowr = wrinkled

24. Dihybrid Crosses GRGrgRgr GR Gr gR gr Gg Rr Gg RRGG RrGGRRGGRR GG rrGG Rr Gg Rr Gg RrGg Rr Gg rr Gg RRGg RR gg rr Gg rrGg rr Gg Rr gg Rrgg RR gg Rr