2. Meet Harry Shields Farmer/judge in Kansas My great-great grandfather Notice: –Nose –Hairline –Inner eye canthus We all have relatives characteristics!…sooo…?

3. “ mommy. Where do babies …” Early conceptions about reproduction…storks? What problems would you see in these? Discovery of egg and sperm leads to questions

4. Gregor Mendel Childhood & schooling Applied math? (stats) Simple experiments Success??? Well???

5. MENDELIAN GENETICS Introduction… blending vs particle theory? Mendel’s experiments…peas again!! His results…what do they mean? Some terminology to make genetics easier How to solve monohybrid problems

6. Some terms to know Homozygous… dominant & recessive heterozygous alleles Punnett square Genotype Phenotype Gene, gene locus Incomplete dominance or codominance Monohybrid cross Dihybrid cross Test cross Pleiotropy Epistasis Polygenic inheritance

7. Some terms to know Crossing over Sex-linked genes Sex-influenced genes Autosome Germ cell Karyotype Gene locus polyploidy Turners/Kleinfelters/XXX Down syndrome Nondisjunction Amniocentesis Chorionic villus sampling Linked genes

8. BLENDING vs PARTICLE? Evidence for blending… Consequences of blending theory Evidence for particle… Consequences of particle theory Evolution/natural selection seems to favor which theory???

9. Mendel’s “factors” Believed in particulate theory Felt that ‘factors’ were contributed equally from male/female Thought these ‘factors’ separated during meiosis and recombined at zygote Gene=location Occur in pairs of alleles One from male One from female

10. Mitosis vs meiosis

12. Garden peas & heredity Blending vs particle theories… No real evidence for either, until… Science in the early 19 th century Mendels 7 traits!!

13. Mendel’s “lucky seven” Seed shape Seed color Pod shape Pod color Flower color Flower position Plant height

17. Quiz What are purebreeding plants (homozygous)? What is a hybrid (heterozygous)? What is the ratio of dominant to recessive in the F1 generation? What is meant by segregation of alleles? What is meant by independent assortment of alleles?

20. Mendel’s pea experiment ‘pure breeding plants’ Blend or…? F1 generation suggests what…? F2 generation is the real proof…!! conclusions

21. Results Mathematical analysis solved mystery F1 & F2 generations what did 3:1 ratio mean?? Dominant/recessive independent assortment test crosses prove theory

22. quiz What is the F2 phenotypic ratio of dom/rec plants? What is the genotypic ratio of the F2 generation? What is a test cross? Why was Mendel able to solve such a difficult problem when others failed?

23. Mendel’s ‘laws’ Segregation of alleles- remember meiosis? Independent assortment Dominance and recessiveness

24. How to do a punnett square

25. What is a test cross (back cross) What if you know the phenotype but not the genotype? What genotype do you always know? Two predicted outcomes

26. Heterozygous Homozygous

27. Some problems?? If a brown-eyed man marries a blue-eyed woman and they have brown-eyed 10 kids (!) can you be certain that he is homozygous? What if the 11 th is blue-eyed? A brown-eyed man, whose father was brown- eyed and whose mother was blue-eyed, marries a blue-eyed woman whose father and mother were brown-eyed have a blue-eyed son. Give the genotypes for all?

28. Multiple Alleles??? Replace lost blood??? Why didn’t it work? Landsteiner solves the mystery (1900) by… But how could genetics explain it with just 2 genes…?

29. “it’s in the blood”…? ‘mixed’ blood often agglutinates (thus death) But sometimes it doesn’t? Why? Landsteiner postulates 4 phenotypes based on unseen ‘antigens’ and antibodies in blood!

31. Blood Types?? Multiple alleles

32. But how to explain the genetics? Each parent contributes an “element” (gene) The A and B genes are both dominant or said to be “codominant” and the o is recessive thus Three genes (taken only two at a time) code for blood type…producing 4 possible phenotypes and six genotypes…what are they?

33. The Simpsons and Nelsons Both the Simpsons and Nelsons had baby boys the same day in the same hospital. Ricky went home with the Simpsons and Bart the Nelsons. Soon, odd behaviors in both households suggested that something was terribly wrong!! Could they have been switched at birth?? Blood tests were doneand…

34. The Simpsons and Nelsons Homer both had type A while Marge had type B. Ricky had type o. (Oh No!!)… Ozzie and Harriet had type A. Bart had type B… Did a switch occur??… what happened next?

35. But what about pink carnations? Red flower X white flower produces… Pink???

36. But what about pink carnations??

37. Incomplete dominance Neither gene is dominant Intermediates result F2 generation reveal the parental phenotypes…why?

38. Quiz…incomplete dominance Use the example of snapdragons…a red (RR) flower is crossed with a white (WW) flower What is the F1 phenotypic ratio of 2 hybrids (heterozygotes) mating? What is the genotypic ratio?

39. Sex determination in other species Many animal systems have different mechanisms for determining sex Some are variable or changeable!! Why??

40. Male to female sex ratio

42. Sex determination

43. Sex-linked genes Why are more boys than girls color-blind? What is color-blindness? What is a ‘sex-linked’ trait??

44. The retina has, normally, 3 kinds of cones…red, blue and green light sensitive…because of 3 different proteins…blue is on chr 7 but red/green on X chr are 98% similar and a mutation causes either the loss of red or green sensitivity

45. Genetics of Color-Blindness A man and his wife have normal color vision, but a daughter with color-blindness. He sues his wife for divorce for infidelity. You be the judge!

93. Down Syndrome Nondisjunction of 21 st chromosomes Variable effects Amniocentesis can detect trisomy 21 early… Difficult questions remain for the parents…