1. Patterns of Inheritance

2. Gregor Mendel “Father” of genetics Mid 1800s Austrian monk
Studied math and science in Vienna
Taught high school
Tended to the monastery garden
Conducted his genetic studies in pea plants

3. Anatomy of a Flower

4. True-breeding Strains
Mendel used “self-pollination” to obtain true breeders

5. Cross-Pollination

6. Characteristics vs. Traits
Plant height
Pea color
Flower color
Pea shape
Flower position
Tall, short
Yellow, green
Purple, white
Wrinkled, smooth
Axial, terminal
Characteristics vs. Traits

8. Mendel’s 4 Hypotheses
1. There are alternative versions of genes that account for variations in characteristics.

9. Mendel’s 4 Hypotheses
2. For each characteristic, an organism inherits 2 alleles—one from each parent.

10. Mendel’s 4 Hypotheses
3. If the 2 alleles of an inherited pair differ, then one determines the organism’s appearance.

11. Law of Segregation Mendel’s 4 Hypotheses
4. A sperm or egg carries only 1 allele for each characteristic because the 2 alleles segregate (separate) during meiosis.
Law of Segregation

12. Dihybrid Crosses: Mendel’s Law of Independent Assortment

13. Dihybrid Crosses: Mendel’s Law of Independent AssortmentX

14. In Dihybrid Crosses, Why Don’t We See This….?

15. The Rules of Probability

16. Traits Thought to be Controlled by a Single Gene

17. Family Pedigrees

18. Autosomal Recessive Pedigree

19. Why We Have Laws Against Marrying Your First Cousin!

20. Single-Gene Autosomal Disorders

21. Welcome to Non-Mendelian Genetics (which is MOST of Human Genetics!)

22. Incomplete Dominance

23. Incomplete Dominance

24. Incomplete Dominance

25. Codominance: ABO Blood Groups

26. Codominance: ABO Blood Groups

27. Codominance: ABO Blood Groups

28. Why is it so important to give a patient the correct blood type?

29. Pleiotropy
One gene has the ability to influence several characteristics

30. Polygenic Inheritance
The additive effects of 2 or more genes on a single phenotypic characteristic.

31. Polygenic Inheritance

32. Polygenic Inheritance

33. Don’t Forget About the Influence of the Environment!

34. Sex Chromosomes and Sex-Linked Genes

35. Sex Determination in Humans

36. Sex Determination in Humans

37. Red-Green Colorblindness: A Sex-Linked Recessive Trait

38. Red-Green Colorblindness: A Sex-Linked Recessive Trait

39. Red-Green Colorblindness: A Sex-Linked Recessive Trait

40. Hemophilia in the Russian Royal Family

41. The Genetics of Calico Cats: Why they are always female!
Barr Body Formation

42. The Genetics of Calico Cats: Why they are always female!