2. Introduction to Genetics

3. Abbott Gregor Mendel The “Father of Genetics” 1822-1884 As you watch this video clip write down 3 facts about Gregor Mendel https://www.youtube.com/watch?v =0vAAf4g5iF8 https://www.youtube.com/watch?v =YxKFdQo10rE

4. 3 Main Principles

5. 1) Segregation Alleles are separated during reproduction; one from each parent. –Ex. BB (mom) bb (dad) »Child (Bb)

6. Segregation Alleles are separated during reproduction; one from each parent.

7. 2) Dominance In an heterozygous situation of alleles (Aa for example), one trait will be dominant (show up) over the other. Ex. B= Brown eyesb= blue eyes BB= Brown eyesbb= blue eyes Bb= Brown eyes

8. 3) Independent Assortment Which allele an organism receives has no effect on other traits which may be displayed. Ex. Hair color has no effect on Brain size.

9. So- What is Genetics? The study of the path of characteristics…ie where they came from, where they are and where they may go...

10. Why study genetics? Because genetics determine WHO WE ARE !!!

11. Alleles The different forms of a gene A, B, Z (anything!)

12. Homozygous -Purebred Two alleles of the same dominance (either both AA or both aa)

13. Heterozygous-Hybrid Two letters (alleles) that are different = hetero Ex. Aa or Zz or Bb.

14. Dominant /Recessive Dominant is represented as an UPPER CASE Ex. A Recessive is represented as lower case. Ex. a

15. Phenotype The physical traits that a person actually shows!

16. Genotype The genes that a person carries but does not show. Ex. A person may carry a trait for blue eyes but actually have Brown eyes!

17. Class survey Question- Are dominant traits seen more often than recessive traits?

18. Free earlobes/Attached earlobes

19. Widows Peak/No widows peak

20. Cleft chin

21. Smile dimples

22. Two Factor Crosses

23. Incomplete Dominance A situation where one trait is not completely dominant over the other. The heterozygous trait is in between the homozygous phenotypes.

24. Codominance A situation in which both alleles contribute to the phenotype of the organism.

25. Multiple alleles Genes that have more than two alleles.

26. Polygenic Traits Genetic traits that are a combination of several genes.