1. Genetics

2. Heredity – characteristics inherited from parents to offspring through genes Genetics - The study of genes and heredity

3. Traits Characteristics that are inherited through genes –Genes are a portion of an organism’s DNA –Each organism has two copies of each gene –Genes have different forms called alleles

4. Gregor Mendel A monk in the 1800s First to identify heredity Studied the traits in garden peas –Tall/short –Round/wrinkled –Green/yellow pods –Purple/white flowers Why peas???

5. Parent or “P” Generation The 2 organisms that are used to reproduce

6. F1 Generation The offspring - babies

7. F2 generation The babies of the F1 or the grandchildren of the P generation –Mendel noticed that in his peas, the white trait that disappeared with the F1 generation reappeared, but in a very small ratio compared to the purple trait

8. The Rule of Dominance There are two contrasting traits/alleles –Ex: tall or short –Another example pod color – green/yellow Alleles can be either dominant or recessive (strong or weak) –Dominant alleles are observable –Recessive alleles are not observable when the dominant allele is present – they are hidden (masked) by the dominant allele

10. The Law of Segregation The two allleles for a gene separate when forming a sperm and egg

11. Law of Independent assortment Alleles for different genes are distributed to sperm and egg independently and randomly –Different alleles do not affect each other Could be –tall and fat –Short and thin –Tall and thin –Short and fat Why all siblings do not look exactly alike

12. Genotype Created after fertilization of an egg by sperm The copies of alleles or genes that an organism has Genetic make-up ontrols the phenotype Ex: BB, Bb, bb

13. Phenotype The way an organism physically looks –Ex: Brown hair, tall –Determined by the genotype

14. How can three genotypes only produce two phenotypes?

15. Homozygous – (Homo: same) Pure/true breeding When an organism has 2 copies of the same allele BB – homozygous dominant bb – homozygous recessive

16. Heterozygous (Hetero: different) Hybrid When an organism has 2 different alleles for a gene one capital; one lower case Bb, Gg etc.

17. Punnett Square A chart used to predict the probability of traits represented among offspring Why it is only a prediction?

18. Monohybrid One cross because you are looking at only one trait

19. Monohybrid Punnett Square Problems Height – tall is dominant to short Symbol for tall _______ Symbol for short _____ Phenotype – –Homozygous tall male X short female Genotype –Male _____ X Female ______

20. P1 Punnett Square –F1 genotype ratio –F1 phenotype ratio

21. Monohybrid Punnett Square Problems Height – tall is dominant to short Symbol for tall _______ Symbol for short _____ Phenotype – –Heterozygous male and female Genotype –Male _____ X Female ______

22. F1 Punnett Square –F2 genotype ratio –F2 phenotype ratio