1. Genetic Vocabulary True – breeding – over many generations of self polinating, produce only the same traits as the parent plant. (eg: purple flower plants only produce purple flower plants) Hybridization – the mating (or crossing) of two true breeding varieties (eg: purple x white)

2. Homozygous - pair of identical alleles for a gene Heterozyous - two different alleles for a gene Phenotype –organism’s trait (physical appearance) Genotype – genetic makeup (expressed with alleles)

3. Genetics heredityThe study of heredity. Gregor Mendel (1860’s) principles geneticsbreeding garden peasGregor Mendel (1860’s) discovered the fundamental principles of genetics by breeding garden peas.

4. Mendel’s Experiment P generation – true breeding parents F 1 generation – hybrid offspring of P generation F 2 generation – offspring of hybrids

5. Mendel’s Model Gene - –Character – a heritable feature that varies among individuals (eg: flower color) 1. Alternative versions of genes called alleles –(genes – factors passed from parent to offspring) Account for variations Ex: white flower allele or purple flower allele

6. 2. Inherit two alleles for each trait 3. Principle of Dominance If two alleles differ, one determines appearance, dominant allele; the other has no noticeable affect, recessive allele 4. Law of Segregation – the two alleles for a heritable character segregate during gamete formation

7. Homologous Chromosomes eye color locus b = blue eyes eye color locus B = brown eyes Paternal Maternal This person would have brown eyes (Bb)

8. Meiosis - eye color Bb diploid (2n) B b meiosis I B B b b sperm haploid (n) meiosis II

9. Punnett square and Probability Punnett square combinationsgametesA Punnett square is used to show the possible combinations of gametes or probability of genotypes Monohybrid CrossMonohybrid Cross single trait.tracks the inheritance of a single trait.

11. P generation Breed the P generation purple (PP) vs. white (pp) flowerspurple (PP) vs. white (pp) flowers p p PP

12. purple (PP) vs. white (pp) flowers p p PP PpPp PpPp PpPp PpPp All Pp purple (heterozygous) produces the F 1 generation

13. F 1 generation Breed the F 1 generation purple (Pp) vs. Purple (Pp) flower plantspurple (Pp) vs. Purple (Pp) flower plants P p Pp

14. Purple (Pp) vs. purple (Pp) flower plants PP PpPp PpPp ppP p Pp produces the F 2 generation 1/4 (25%) = PP 1/2 (50%) = Pp 1/4 (25%) = pp 1:2:1 genotype 3:1 phenotype 3:1 phenotype

15. Monohybrid Cross ExampleheterozygotesExample:Cross between two heterozygotes for brown eyes (Bb) BB = brown eyes Bb = brown eyes bb = blue eyes B b Bb Bb x Bb male gametes female gametes

16. Monohybrid Cross BB Bb bbB b Bb Bb x Bb 1/4 = BB - brown eyed 1/2 = Bb - brown eyed 1/4 = bb - blue eyed 1:2:1 genotype 3:1 phenotype

17. Test Cross Perform a test cross to determine the genotype of an organism with a dominant phenotype Cross the organism with the unknown genotype with an organism that is homozygous recessive

19. Dihybrid Cross two traits.A breeding experiment that tracks the inheritance of two traits. Mendel’s “principle of independent assortment”Mendel’s “principle of independent assortment” (metaphase I) a.each pair of alleles segregates independently during gamete formation (metaphase I) 2 n (n = # of heterozygotes) b.formula: 2 n (n = # of heterozygotes)

20. Independent Assortment

21. Dihybrid Cross Example:roundyellowExample:cross between round and yellow heterozygous pea seeds. R= round r= wrinkled Y= yellow y= green RY Ry rY ry RY Ry rY ry RY Ry rY ry x RY Ry rY ry possible gametes produced RrYyRrYy RrYy x RrYy

22. Dihybrid Cross RYRyrYry RYRy rY ry

23. RRYY RRYy RrYY RrYy RRYy RRyy RrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy Round/Yellow: 9 Round/green: 3 wrinkled/Yellow: 3 wrinkled/green: 1 9:3:3:1 phenotypic ratio RYRyrYryRY Ry rY ry

24. Incomplete Dominance F1 hybrids in betweenphenotypesF1 hybrids have an appearance somewhat in between the phenotypes of the two parental varieties. Example:snapdragons (flower)Example: snapdragons (flower) red (RR) x white (WW) RR = red flower WW= white flower W W RR

25. Incomplete Dominance RW W W RR All RW = pink (heterozygous pink) produces the F 1 generation

26. Codominance Two allelesmultiple alleles heterozygous individualsTwo alleles are expressed (multiple alleles) in heterozygous individuals. Example: bloodExample: blood 1.type A= I A I A or I A i 2.type B= I B I B or I B i 3.type AB= I A I B 4.type O= ii

27. Codominance Example:Example:homozygous male B (I B I B ) x heterozygous female A (I A i) IAIBIAIB IAIBIAIB IBiIBiIBiIBi 1/2 = I A I B 1/2 = I B i IAIA IBIB IBIB i

28. Codominance Example:Example: male O (ii) x female AB (I A I B ) IAiIAiIBiIBi IAiIAiIBiIBi 1/2 = I A i 1/2 = I B i i IAIA IBIB i

29. Codominance QuestionQuestion:If a boy has a blood type O and his sister has blood type AB, what are the genotypes and phenotypes of their parents. boy - type O (ii) X girl - type AB (I A I B )

30. Codominance Answer:Answer: IAIBIAIB ii Parents: genotypes genotypes = I A i and I B i phenotypes phenotypes = A and B IBIB IAIA i i

31. Sex-linked Traits sex chromosomesTraits (genes) located on the sex chromosomes Example:fruit fliesExample:fruit flies redwhite (red-eyed male) X (white-eyed female)

32. Sex-linked Traits Sex Chromosomes XX chromosome - femaleXy chromosome - male fruit fly eye color

33. Sex-linked Traits Example:fruit fliesExample:fruit flies (red-eyed male) X (white-eyed female) Remember:Y chromosomeRemember: the Y chromosome in males does not carry traits. RR = red eyed Rr = red eyed rr = white eyed Xy = male XX = female XrXr XRXR y XrXr

34. Sex-linked Traits X R X r X r y 1/2 red eyed and female 1/2 white eyed and male XrXr XRXR y XrXr

35. Population Genetics genetic changespopulationsThe study of genetic changes in populations. microevolutionary changes populationsThe science of microevolutionary changes in populations. Hardy-Weinberg equilibrium:Hardy-Weinberg equilibrium: the principle that shuffling of genes that occurs during sexual reproduction, by itself, cannot change the overall genetic makeup of a population. Hardy-Wienberg equation:1 = p 2 + 2pq + q 2Hardy-Wienberg equation:1 = p 2 + 2pq + q 2

36. Need to remember the following:Need to remember the following: p 2 = homozygous dominant 2pq = heterozygous q 2 = homozygous recessive Important

37. (recessive trait) heterozygoushomozygousdominantIguanas with webbed feet (recessive trait) make up 4% of the population. What in the population is heterozygous and homozygous dominant. Question:

38. Answer: 1. q 2 = 4% or.04 q 2 =.04 q =.2 2. then use 1 = p + q 1 = p +.2 1 -.2 = p.8 = p 3. for heterozygous use 2pq 2(.8)(.2) =.32 or 32% 4. For homozygous dominant use p 2.8 2 =.64 or 64%

39. Hardy-Wienberg equation 1 = p 2 + 2pq + q 2 64% = p 2 = homozygous dominant64% = p 2 = homozygous dominant 32% = 2pq= heterozygous32% = 2pq= heterozygous 04% = q 2 = homozygous recessive04% = q 2 = homozygous recessive 100%100%