Basic Mendelian Genetics based on BSCS Blue and Campbell Biology

1. Classical Genetics

2. The Work and Conclusions of Gregor Mendel Father of genetics Monk in Austria 1865 Studied patterns of inheritance in peas

3. Why Peas?

4. Why Peas? Self-fertilization produces true breeding generations

6. Why Peas? Read Concept 2 Click Animation and View

7. Mendel’s Work Some traits are dominant and some are recessive Read concept 3 Click animation and view Read concept 4 Click animation and view

9. Mendel’s Work Alleles are represented by the first letter of the dominant trait Pea plant flower color (trait) Purple or white Purple is dominant over white Alleles are represented as P=purple p=white

11. Mendel’s Work Describing Traits (Tall or short plants) Genotype The actual genetic make-up of an organism the “genes” Phenotype The physical appearance or form observed the “physical”

12. Mendel’s Work Possible Genotypes (TT Tt tt) Homozygous The two alleles for the trait are identical TT homozygous dominant (purebred dominant) tt homozygous recessive (purebred recessive) Heterozygous The two alleles for the trait are different Tt heterozygote (hybrid)

13. Mendel’s Work

14. Mendel’s Work Read Concept 5 Click animation and view Complete visual organizer of Mendel’s pea plant experiment

15. 1. Law of Dominance Alleles for a trait are either dominant or recessive The dominant form is expressed and the recessive form is hidden The only way to express a recessive trait is if there are two copies of the recessive allele Mendel’s Conclusions

18. Test Cross

19. Dihybrid Cross

21. Incomplete Dominance

22. “ Dominant” gene does not fully express itself to mask the effect of the recessive gene A pattern of inheritance in which the phenotype of a heterozygous individual is intermediate between those of the parents Genotypic ratio is equal to phenotypic ratio

23. Co-Dominance Two or more alleles are fully dominant When present together they are both expressed ABO Blood Groups exhibit co-dominace

32. Sex Inheritance Sex Chromosomes X or Y XX is female XY is male Read concept 9 Click animation and view

33. Sex-Linked Inheritance Genes linked to sex chromosomes