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Genetics Review Powerpoint

Genetics Review Powerpoint. MENDEL’S PEA EXPERIMENTS. P 1 = Parental. F 1 = Filial (pffspring). F 2 = Filial (pffspring). http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif. Refresh your “Bio Brain” about: GENETICS VOCAB

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Genetics Review Powerpoint

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  1. Genetics Review Powerpoint

  2. MENDEL’S PEA EXPERIMENTS P1 = Parental F1 = Filial (pffspring) F2 = Filial (pffspring) http://hus.yksd.com/distanceedcourses/YKSDbiology/lessons/FourthQuarter/Chapter11/11-1/images/MendelExperiment.gif

  3. Refresh your “Bio Brain”about: GENETICS VOCAB DOMINANT: RECESSIVE: HOMOZYGOUS (pure-breeding): HETEROZYGOUS (hybrid): GENOTYPE: PHENOTYPE:

  4. Refresh your “Bio Brain” about: GENETICS VOCAB DOMINANT: RECESSIVE: gene that hides anotherrepresented by capital letter gene that is hidden by anotherrepresented by lower case letter

  5. Refresh your “Bio Brain” about: GENETICS VOCAB HOMOZYGOUS (pure-breeding): HETEROZYGOUS (hybrid): Organism with two identical alleles for a gene TT OR tt Organism with two different alleles for a gene Tt

  6. Refresh your “Bio Brain” about: GENETICS VOCAB GENOTYPE: PHENOTYPE: Genetic make up of an organism “What genes it has” Appearance of an organism “Way it looks”

  7. Probability is the likelihood that an event will occur It can be written as a: Fraction ____ Percent ____ Ratio ____ 1/4 25% 1:3

  8. http://www.arborsci.com/CoolStuff/CoinFlip.jpg COIN FLIP There are 2 possible outcomes: HEADS TAILS The chance the coin will land on either one is: ____ ____ ____ Alleles segregate randomly just like a coin flip. . . So can use probability to predict outcomes of genetic crosses. 1/2 1:1 50% NOT 1:2!

  9. IN PEAS: R = round T = tall Y = yellow peas P = purple flowers r = wrinkled t = short y = green peas p = white flowers

  10. Make a cross between a HOMOZYGOUS ROUND pea plant X PURE-BREEDING WRINKLED pea plant Show probabilities for: genotypes and phenotypes of possible offspring R R GENOTYPE PHENOTYPE ____________ ___________ _______ show dominant phenotype _______ show recessive phenotype Rr r r ROUND Rr Rr Rr Rr 100% 4/4 0% 0/4

  11. Make a cross between a HOMOZYGOUS TALL pea plant X HOMOZGYOUS SHORT pea plant Show probabilities for: genotypes and phenotypes of possible offspring T T GENOTYPE PHENOTYPE ____________ ___________ _______ show dominant phenotype _______ show recessive phenotype Tt t t TALL Tt Tt Tt Tt 100% 4/4 0% 0/4

  12. WHAT’s THE PATTERN? HOMOZYGOUS DOMINANT pea plant X HOMOZGYOUS RECESSIVE pea plant DO ONE IN YOUR HEAD HOMOZYGOUS PURPLE FLOWER X HOMOZGYOUS WHITE FLOWER pea plants ALL Pp 100% PURPLE FLOWERS 0% WHITE FLOWERS

  13. IN PEAS: R = round T = tall Y = yellow peas P = purple flowers r = wrinkled t = short y = green peas p = white flowers

  14. Make a cross between a HETEROZYGOUS YELLOW pea plant X HYBRID GREEN pea plant Show probabilities for: genotypes and phenotypes of possible offspring GENOTYPE PHENOTYPE ____________ _______________________ _______________________ ___________ _______ show dominant phenotype _______ show recessive phenotype _________ phenotypic ratio Y y YY YELLOW Yy YELLOW Y y YY Yy Yy yy yy GREEN 75% 3/4 25% 1/4 3:1 1:2:1 ____________ genotypic ratio

  15. Make a cross between a HETEROZYGOUS TALL pea plant X HETEROZYGOUS SHORT pea plant Show probabilities for: genotypes and phenotypes of possible offspring GENOTYPE PHENOTYPE ____________ _______________________ _______________________ ___________ _______ show dominant phenotype _______ show recessive phenotype _________ phenotypic ratio T t TT TALL Tt TALL T t TT Tt Tt tt tt SHORT 75% 3/4 25% 1/4 3:1 1:2:1 ____________ genotypic ratio

  16. WHAT’s THE PATTERN? HOMOZYGOUS DOMINANT pea plant X HOMOZGYOUS RECESSIVE pea plant DO ONE IN YOUR HEAD HOMOZYGOUS PURPLE FLOWER X HOMOZGYOUS WHITE FLOWER pea plants ______ PURPLE?______ WHITE? _____ PP? _____ Pp? _____ pp? _________ genotypic ratio _______ phenotypic ratio 75% 25% 25% 50% 25% 1:2:1 3:1

  17. POSSIBLE PARENT GAMETES? __________________________ INDEPENDENT ASSORTMENT

  18. POSSIBLE PARENT GAMETES? TTRR ________________________ TR TR TR TR INDEPENDENT ASSORTMENT

  19. POSSIBLE PARENT GAMETES? ttrr ________________________ tr tr tr tr INDEPENDENT ASSORTMENT

  20. TR TR TR TR tr tr tr tr GENOTYPE _____________ PHENOTYPE ____________ TrRr TrRr TrRr TrRr TtRrTtRr TtRr TtRr TtRr TtRr TtRr TtRr TtRrTtRr TtRr TtRr TtRr TALL & ROUND

  21. POSSIBLE PARENT GAMETES? TtRr ________________________ TR tR tr Tr INDEPENDENT ASSORTMENT

  22. POSSIBLE PARENT GAMETES? RrYy ________________________ RY rY ry Ry INDEPENDENT ASSORTMENT

  23. RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green

  24. RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green RRYY RRYy RrYY RrYy RRYy RRyy RrYy RryyRrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy

  25. RY Ry rY ry RY Ry rY ry ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 RRYYRRYyRrYY RrYy RRYy RRyy RrYy RryyRrYY RrYyrrYY rrYy RrYyRryy rrYyrryy 3 3 1 Sign of HETEROZYGOUS DIHYBRID cross What’s the pattern?

  26. 9 ____ ____________ TRAIT 1 ; ____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 dominant dominant 3 dominant recessive 3 recessive dominant 1 recessive recessive __________ratio is a clue that it’s a ____________________________cross 9:3:3:1 HETEROZYGOUS TWO gene

  27. NON-MENDELIAN INHERITANCE INCOMPLETEDOMINANCE COMPLETEDOMINANCE F2 generation- Not a 3:1 ratio Heterozygote= blended intermediate phenotype http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

  28. NON-MENDELIAN INHERITANCE CO-DOMINANCE HETEROZYGOTE: Both traits are expressed together (NO BLENDING) Roan horse has BOTH red & whitehair (NOT A PINK HORSE! An A allele AND a B allele make BOTH A and B GLYCOPROTEINS= AB Blood type

  29. Make a cross between TWO HETEROZYGOUS ROAN HORSES Show probabilities for: genotypes and phenotypes of possible offspring GENOTYPE PHENOTYPE ____________ _______________________ _______________________ ___________ _________ phenotypic ratio R W RR RED 25% 1/4 RW 50% 1/2 ROAN R W WW WHITE RR RW RW WW 25% 1/4 1:2:1 1:2:1 ____________ genotypic ratio

  30. Make a cross between a HOMOZYGOUS RED HORSE and HOMOZYGOUS WHITE HORSE Show probabilities for: genotypes and phenotypes of possible offspring R R GENOTYPE PHENOTYPE ____________ ___________ _________ ROAN offspring W W RW RW RW RW RW ROAN 100%

  31. NON-MENDELIAN INHERITANCE ALLELES: ____ ____ ____ BLOOD TYPE MULTIPLE ALLELE TRAIT & CODOMINANT TRAIT _____ allele is dominant to _____ allele._____ allele is dominant to _____ allele._____ and _____ are CODOMINANT. BOTH SHOW TOGETHER

  32. NON-MENDELIAN INHERITANCE B A O ALLELES: ____ ____ ____ BLOOD TYPE MULTIPLE ALLELE TRAIT & CODOMINANT TRAIT A O _____ allele is dominant to _____ allele._____ allele is dominant to _____ allele._____ and _____ are CODOMINANT. BOTH SHOW TOGETHER O B A B

  33. SEX-LINKED GENES Some genes are carried on SEX chromosomes X-linked recessive disorders:HemophiliaColor blindnessDuchenne Muscular Dystrophy XX= ________________XY = ________________ X-linked traits show up more frequently in malesNo backup X to cover for the “broken” gene FEMALES MALES

  34. X-LINKED Cross a colorblind male with a normal vision (non-carrier) female Xc Y PHENOTYPE100% normal vision 50% normal males 50% carrier females XCXc XCY XCXc XCY XC XC

  35. X-LINKED Cross a hemophilia male with a carrier female Xh Y PHENOTYPE 25%- hemophilia female25%- hemophilia male 25%- normal male 25% - normal (carrier) females XHXh XHY XhXh XhY XH Xh

  36. TEST CROSSES

  37. TEST CROSSESDominant looking parent could have these genotypes: ________ OR __________ Can’t tell which by looking. Test cross used to determine which it is.ALWAYS TESTCROSS WITH A _________________________________Offspring provide clue about genotype of unknown parent. TT Tt HOMOZYGOUS RECESSIVE

  38. TEST CROSSES T T T t tt t t Tt Tt Tt Tt Tt ttTt tt 50% will be TALL 50% will be SHORT All offspring will be TALL If any offspring show the recessive trait . . . unknown parent genotype was ________. If all offspring show the dominant trait . . . still don’t know. BOTH genotypes could produce offspring that look dominant! Tt

  39. Deafness in dogs is caused by a recessive allele. Deaf dogs have the genotype dd. You have a hearing dog. Do a test cross to determine its genotype. D d D D dd Dd Dd Dd Dd d d Dd dd Dd dd An actual test cross results in a litter with: 5 hearing puppies 0 deaf puppies What can you conclude?

  40. Firebreathing (F) in dragons is dominant over NON-firebreathing (f). You have a fire-breathing dragon. What possible alleles could the fire-breathing parent have? _______ OR ________ EXPLAIN how you could use a TEST CROSS to help determine the parental genotype. Show the results of test crossing BOTH OF THE POSSIBLE PARENT GENOTYPES: An actual test cross results in a litter with: 6 firebreathing dragons 1 NON-firebreather EXPLAIN how you could use these results to determine the correct parental genotype.

  41. TEST CROSS Used to determine genotype of unknown DOMINANT LOOKING parent Always cross with HOMOZYGOUS RECESSIVE (EX: tt)Observe offspring-If any offspring show recessive trait… know parent was HETEROZYGOUSIf all offspring show DOMINANT trait . . .Still don’t know genotype. Do another test cross.Both TT and Tt can produce tall offspring with tt cross

  42. DRAGONS An actual test cross results in a litter with: 6 firebreathing dragons 1 NON-firebreather F f F F f f Ff Ff Ff Ff f f Ff ff Ff ff What can you conclude? Unknown parent genotype is FfOnly way you can get a NON-FIREBREATHER

  43. Write a NULL hypothesis that describes the mode of inheritance for the trait (purple eyes) I would expect this pattern in the F1 offspring _______________________________ I would expect this pattern in the F2 offspring ________________________________ THERE IS NO DIFFERENCE BETWEEN THE OBSERVED DATA AND THE EXPECTED DATA IF PURPLE EYES IS A(N) _________________ ____________ TRAIT

  44. + p p p +p +p +p +p ++ +p +p pp + p + + F1 100% wild type F2 75% wild type 25% purple eyed IF YOU IGNORE SEX:If 1000 flies, expect 750 to be wild type and 250 to be purple eyed If you DON’T IGNORE SEX: 375 WT MALES 125 purple eyed MALES 375 WY FEMALES 125 purple eyed FEMALES Calculate Chi-squareDO YOU ACCEPT OR REJECT THE NULL HYPOTHESIS?

  45. H0- There is no difference between the frequencies observed and the frequencies expected if PURPLE eyes is an autosomal recessive trait.

  46. IF GENE is AUTOSOMAL and RECESSIVE TO + MALES:FEMALES 1:1 m m + + +m +m +m +m F1 All = +m (wildtype) + m + m F2 ¼ = ++ 75% wildtype ½ = +m ¼ = mm 25% mutant 3:1 ++ +m +m mm http://www.exploratorium.edu/exhibits/mutant_flies/curly-wings.gif

  47. IF GENE is AUTOSOMAL and DOMINANT TO + MALES:FEMALES 1:1 M M + + +M +M +M +M F1 All = +M (mutant) + M + M F2 ¼ = ++ 25% wildtype ½ = +M ¼ = MM 75% mutant 1:3 ++ +M +M MM

  48. IF GENE is X-linked recessive Different pattern if gene is inherited from mom or dad Mutant mom X wild type dad F1 Xm y X+ Xm F1 X+ y Xm Xm X+Xm X+y XmXm Xmy X+Xm Xmy X+Xm Xmy 25% normal females25% mutant females 25% mutant males25% normal males 50% normal females 50% mutant males When using Virtual fly labChoose ignore sex and see if it changes the ratios

  49. POSSIBLE PARENT GAMETES? RrYy ________________________ RY rY ry Ry INDEPENDENT ASSORTMENT

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