1. The Human Genome Chapter 12-1 & 12-2

2. THINK ABOUT IT What does a can of Diet Coke and this songsong have to do with human genetics? (Answers to come in this slide show!)

3. HUMAN GENETICS Dominant and Recessive Homozygous/Heterozygous work for human genes too!

4. ________ are made by joining ___________ subunits together amino acid Proteins REMEMBER YOUR MOLECULES!

5. REMEMBER YOUR MOLECULES __________ is carried in the ________ of A, T, G, C’s on a _____ molecule DNA Genetic code sequence

6. The sequence of A’s, T’s, G’s & C’s tells the _______ of ________ in the ________ ORDERamino acids protein

7. Changes in the gene code _______________ that is made A change in the genetic code = ________________ MUTATION change the protein

8. KINDS OF MUTATIONS ________ CELLS = ___________ CELLS Somatic cell mutations can: ______________________ ______________________ _____________ BODY Cause cancer Make cell not able to function Kill cell  BUT _________ passed on to offspring WON’T BE SOMATIC

9. Kinds of Mutations ___________ = _________cells (sperm & eggs) GAMETES  Germ cell mutations ________ passed on to offspring CAN BE http://anthro.palomar.edu/biobasis/images/meiosis.gif GERM

10. Mistakes in Meiosis Examples: –Down’s Syndrome (Trisomy-21) –Klinefelter’s Syndrome –Turner’s Syndrome Chromosomes fail to separate properly during meiosis, i.e., nondisjunction ANEUPLOIDY -- an abnormal number of chromosomes

11. ____________- Most mutations have little or no effect on gene ____________. _____________ in code can absorb many mutations without changing the amino acid sequence. UUC and UUU both code for same amino acid MUTATIONS can be: NEUTRAL function REDUNDANCY

12. ____________ - Mutations that produce ______________ are usually harmful. Harmful mutations are associated with many ________________ and can cause ____________ MUTATIONS can be: HARMFUL defective proteins genetic disorders cancer

13. ____________ - Some mutations change proteins that are so vital to life that they cause death, usually before birth. 50% of pregnancies that abort spontaneously have genetic abnormalities MUTATIONS can be: LETHAL

14. Mutations can help an organism _________________ Provide a way for species to change over time ____________- Mutations are also a source of ______________ in the population MUTATIONS can be: BENEFICIAL genetic variation survive and reproduce

15. Mutations can happen: when cells make_________ in copying DNA when cells are exposed to environmental ___________ like __________- X-rays, tanning booths __________ - cigarette smoke, pollutants __________ - HPV _______________ are changes in the genetic material. MUTATIONS mistakes REMEMBER! carcinogens radiation chemicals viruses

16. Mutations that produce changes in a single gene = _________________ Mutations that produce changes in whole chromosomes = _____________________ KINDS OF MUTATIONS GENE MUTATIONS CHROMOSOMAL MUTATIONS Images from: http://www.bbc.co.uk/scotland/education/bitesize/higher/img/biology/genetics_adaptation/mutations/02gene_mutation.gif

17. MANY HUMAN GENES HAVE BECOME KNOWN THROUGH THE STUDY OF GENETIC DISORDERS Many genetic ___________ result from changes in the DNA code so _________________ proteins are produced. DISORDERS NON-FUNCTIONING http://patentdocs.typepad.com/photos/uncategorized/2007/05/28/dna1.gif

18. A mutation that causes a protein to be NON-FUNCTIONAL would appear _______________ to the normal working allele. Examples of __________________________ GENETIC DISORDERS: ____________________ RECESSIVE PHENYLKETONURIA (PKU) TAY-SACHS DISEASE CYSTIC FIBROSIS AUTOSOMAL RECESSIVE

19. Phenylketonuria (PKU) CAUSE: Mutation in gene for an ___________ that __________ an ___________ called phenylalanine Build up causes ________________________ MENTAL RETARDATION ENZYME http://biology.clc.uc.edu/courses/bio104/protein.htm breaks downamino acid X X

20. Phenylketonuria (PKU) ____ babies are ________ for PKU before they leave the hospital. Treatment: Need a diet _____________________ to extend life and ______________ mental retardation If phenylalanine is an _____________, what type of foods should PKU patients avoid? __________________ amino acid PROTEINS ! LOW in phenylalanine PREVENT ALLtested http://labspace.open.ac.uk/file.php/2588/SK195_6_002i.jpg

21. THINK ABOUT IT What does a can of Diet Coke have to do with human genetics? LOOK AT THE WARNING LABEL ! ______________ is made with phenylalanine NUTRASWEET

22. Common Pedigree Symbols Male Female Marriage Affected Female Female Carrier of Sex-linked Recessive Sex Unknown Consanguineous Marriage No Known Pregnancy Unmarried Dead Divorce and Remarried Female Carrier (Heterozygous)

23. Common Pedigree Symbols Pregnancy in Progress 3 Three Males 5 Five Individuals (both sexes) Dizygotic (nonidentical, fraternal) twins Monozygotic (identical) twins Spontaneous Abortion Proband, propositus, or index case Adopted Child

24. Bad Divorce Famous Kid Triplets! Happy new wife!

25. TAY-SACHS DISEASE ___________________ CAUSE: Mutation in gene for an ___________ that breaks down a kind of _________in the developing _________ Build up of lipids in brain cells leads to: mental retardation, blindness, and DEATH in early childhood Found more frequently in people with _______ _____________ ______________, ancestry BRAIN ENZYME Jewish Image from: http://www.djsfoundation.org/images/Steeler%20pics%20Dylan.jpg AUTOSOMAL RECESSIVE MediterraneanMiddle Eastern LIPID

26. Autosomal Recessive Disease manifests itself if offspring inherits one recessive gene from each parent. If parents are carriers, 25% of offspring will have disease.

27. Tay-Sachs Disease 1 in 600 Jews of European descent born with it Lipids deposited in nervous system, causing brain to be damaged -- blindness, loss of movement, mental deterioration. No break down of cellular wastes in lysosome due to absence of hexosaminidase A – mutation causes nerve death Symptoms appear around 6 months of age and victims die due to paralysis and/or convulsions before the age of five.

28. Tay-Sachs Disease What are the genotypes of all individuals in this family? Tt tt Tt TT or Tt tt Tt or TT TT or Tt

29. http://www.biochem.arizona.edu/classes/bioc460/spring/rlm/RLM36.1.html A __________ person who carries a _________ allele for a genetic disorder, but ______________ the disorder themselves is called a _____________ CARRIER heterozygous doesn’t show recessive

30. Polygenic Inheritance Most human characteristics are polygenic, meaning they are influenced by several genes, e.g. skin color influenced by 3-6 genes; also, eye color, height, hair color Complex characters are those that are influenced strongly by both the environment and genes, e.g., diabetes, heart disease, stroke, skin color, height

31. More patterns of inheritance….. Multiple alleles - genes with three or more alleles, e.g., ABO blood groups Incomplete dominance – condition that results in a display of a trait that is intermediate between the two parents X-linked traits – determined by x-linked genes, e.g., color blindness Sex-influenced traits – usually autosomal, e.g. baldness is influenced by testosterone Single-allele traits – more than 200 human traits are governed by single dominant alleles, e.g., Huntington’s disease

32. Single Gene Inheritance Autosomal dominant traits –Huntington’s Disease on chromosome #4 –Marfan Syndrome on chromosome #15 –Breast Cancer on chromosomes #17 Pedigree Analysis Autosomal recessive traits –Tay-Sachs Disease on chromosome #15 –Cystic Fibrosis on chromosome #7 –Sickle Cell Anemia on chromosome #11 X-Linked Disease (Sex-Linked) –Hemophilia--Duchenne’s muscular dystrophy – Color Blindness

33. Multiple Alleles Blood type, using I gene. Human blood types include: Phenotype Genotype –AI A I A or I A i –BI B I B or I B i –ABI A I B (Universal Recipient) –Oii (Universal Donor) If a child has type O blood and its mother has type A, could a type B man be the father? Why couldn’t a blood test be used to prove he is the father?

34. CYSTIC FIBROSIS CAUSE: Loss of 3 DNA bases in a gene for the _____________ that transports _________ so salt balance is upset Causes a build up of _________________ in lungs and digestive organs. thick mucous protein Image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing ©2006 Cl - ions

35. Cystic Fibrosis Found in Caucasians. –Most common lethal genetic disorder among white Americans. –Autosomal recessive on chromosome 7 Thick mucus produced in lungs, intestines, and pancreas. 1/20 of Caucasian population are carriers. –One in 2,000 children born to white Americans inherits the disorder. –CF kills ~500 children and young adults each year.

36. A mutation that codes for a new protein whose action masks the normal allele appears as a ______________ mutation. Examples of _________________________ GENETIC DISORDERS: ____________________ DOMINANT Huntington’s disease Achondroplasia AUTOSOMAL DOMINANT

37. HUNTINGTON’S DISEASE ______________________ CAUSE: Extra 40-100 ______________ at end of gene on chromosome 4 The _____________... the more __________ the symptoms. severe CAG repeats http://www.healthsystem.virginia.edu/internet/huntdisease/images/cag.gif more repeats AUTOSOMAL DOMINANT

38. HUNTINGTON’S DISEASE Causes progressive _____ of ________________ and ___________function loss muscle control mental 1 in 10,000 people in U.S. have Huntington’s disease http://www.scielo.br/img/revistas/bjmbr/v39n8/html/6233i01.htm Huntington’s brain Normal brain

39. A person with Huntington’s disease has a _____ chance of passing the disorder on to their offspring. Problem: Symptoms of disorder usually don’t show until ____________... so you don’t know you have it until ________ you have had children. 50% MIDDLE AGE AFTER

40. Huntington’s Disease Begins to show up by age 45-55, within 10- 20 years, death is eminent. Progressive degeneration of nervous system; irregular body movements and slurred speech. If one parent has HD, offspring have 50% chance of inheriting disease. Autosomal dominant on chromosome 4; 1 in 10,000 births

41. Huntington’s Disease What are the genotypes of the parents? Hh hh

42. THINK ABOUT IT What does the song have to do with human genetics? “This Land is My Land” was written by a musician named Woody Guthrie before he began to show the symptoms of Huntington’s disease. Click to hear Woody’s song

43. Woody Guthrie had a son named Arlo that was a popular musician during the 70’s Before 1993 there was no test for Huntington’s. If one of your parents showed symptoms, you had to wait to see if it had been passed on to you. Click to hear one of Arlo’s songs

44. Arlo Guthrie is still performing today. He never developed symptoms for Huntington’s disease. http://www.jimdirden.com/woodyfest2004/artists/index_3.htm If there is no cure, would YOU want to be tested and find out if you have the gene? http://webs.wichita.edu/depttools/depttoolsmemberfiles/accomp/question_mark%20(WinCE).jpg

45. ACHONDROPLASIA (One kind of Dwarfism) CAUSE: ___________________________ gene 200,000 “little people” worldwide One of oldest known disorders – seen in Egyptian art AUTOSOMAL DOMINANT 1 in 20,000 births

46. ACHONDROPLASIA (One kind of Dwarfism) Normal size head and torso; short arms and legs Problem with way cartilage changes to bone as bones grow

47. DISORDERS CAUSED BY ____________________ ____________________ SICKLE CELL DISEASE CAUSE: T changed to A in gene for __________________ (protein in red blood cells that carries oxygen in blood) HEMOGLOBIN AUTOSOMAL CODOMINANT ALLELES

48. SICKLE CELL DISEASE SYMPTOMS: _____________ become sickle shaped in persons with ______ sickle cell ________ RED BLOOD CELLS TWO ALLELES

49. SICKLE CELL DISEASE Circulatory problems Cells stick in capillaries Loss of blood cells (anemia) Organ damage (brain, heart, spleen) Can lead to DEATH

50. SICKLE CELL DISEASE More common in _________________ 1 in 500 = have sickle cell disease 1 in 10 = carriers for allele Also affects persons of _______________ and _________________ descent Why do so many African Americans carry the sickle cell allele? AFRICAN AMERICANS MEDITERRANEAN MIDDLE EASTERN

51. SICKLE CELL DISEASE Many can trace their ancestry to west central Africa where ___________, a serious parasitic disease that infects red blood cells is common. Images from: http://en.wikipedia.org/wiki/Malaria MALARIA Watch a video about sickle cell and malaria

52. A person who is __________________ for the ____________allele (ss) will have _______________ A person who is _________________ for normal hemoglobin alleles will have normal blood cells, but can become infected with __________ (SS) A _________________ person (Ss) (with one normal/one sickle cell allele) is generally healthy and has the benefit of being _________ to malaria HOMOZYGOUS sickle cell sickle disease HOMOZYGOUS malaria HETEROZYGOUS resistant

53. A __________ is a picture of an organism’s chromosomes KARYOTYPE

54. Chromosomes that determine the sex of an organism = _________________ All other chromosomes = _________________ Sex chromosomes autosomes Humans have two sex chromosomes and _____ autosomes X y 44 http://www.angelbabygifts.com/

55. SEX DETERMINATION XX = Xy = female male

56. Who decides? Mom can give X Dad can give X or y SO ____ determines sex of the baby. If dad gives X with mom’s X = girl If dad give y with mom’s X = boy X X X y X X y Dad

57. SEX CHROMOSOMES CAN CARRY OTHER GENES TOO = ___________________ SEX LINKED TRAITS These traits show up in different _______________ in males and females because they move with the sex chromosomes percentages

58. Y-LINKED GENES: Genes ______________ chromosome EXAMPLE: Hairy pinna _________genes _____ show up _______ Y linked in males carried on Y ONLY

59. ____________ GENES: are carried on the X chromosome X-linked recessive disorders show up _____________ in ______ than females because males only have ______ X chromosome. MALES X-LINKED ONE MORE frequently

60. Males ONLY HAVE ONE X They either have the disorder DEFECTIVE NORMAL They are normal Or

61. FEMALES HAVE TWO X CHROMOSOMES Females have one normal gene that works. NORMALDEFECTIVE Females __________ defective recessive alleles to show the disorder need 2

62. The X chromosome in males... flies WITHOUT a copilot!... there’s NO BACK UP X to help them!

63. Examples of ________________________ DISORDERS: ____________________ HEMOPHILIA COLORBLINDNESS DUCHENNE MUSCULAR DYSTROPHY X-LINKED RECESSIVE

64. HEMOPHILIA CAUSE: Mutation in genes for __________________ carried ______ chromosome Blood clotting proteins are missing so person with this disorder can’t stop bleeding when injured; can ________________ from minor cuts or suffer internal bleeding from bruises or bumps. bleed to death Blood clotting proteins on X

65. Hemophilia -- “Bleeder’s Disease” Deficient blood coagulation due to absence of coagulation factor 8 that helps cause blood to clot. 50% of daughters will also be carriers. XHXhXHXh XHYXHY 1 in 7,000 born with it X-linked recessive on chromosome X

66. HEMOPHILIA Treatment: Need ____________ of normal clotting proteins to stop bleeding _____________ in ______ because it is X-linked, but females with ______ recessive hemophilia alleles will also show the trait. 1 in 10,000 males has hemophilia injections males TWO More common

67. COLORBLINDNESS CAUSE: Mutation in one of three genes for _______________ carried on X chromosome Persons with this disorder have trouble distinguishing colors. _________________ colorblindness is most common Seen in 1 in 10 males 1 in 100 females Red-green Color vision http://gizmodo.com/gadgets/peripherals/samsung-develops-lcd-for-colorblind-036306.php

68. Red-Green Color Blindness

69. Duchenne Muscular Dystrophy CAUSE: deletion in gene that codes for a _______________ Results in ____________________ and loss of ___________________ http://www.cadenhead.org/workbench/gems/jerry-lewis-telethon.jpg http://www.tokyo-med.ac.jp/genet/chm/dei.gif muscle protein progressive weakening skeletal muscle

70. Duchenne Muscular Dystrophy (DMD) SYMPTOMS: 1 in 3000 male births Appears before age 5 Progressive muscle weakening Most in wheelchair by age 13 Eventually lethal

71. What’s the pattern: ________ traits show up _______ in _______ __________________ traits: ______________________ than females. ________________ can be ________. _______________________ traits: BOTH ______ & _________ can be ________ Y-linked ONLY males X-linked recessive more common in males AUTOSOMAL RECESSIVE ONLY FEMALES carriers MALES FEMALES carriers

72. ________________ Abnormalities 1 infant in 200 newborns has a chromosomal abnormality 28% of first trimester miscarriages have a chromosomal abnormality Abnormalities in larger chromosomes don’t usually survive CHROMOSOMAL

73. ____________________________: Change in the ______________ or ____________ of chromosomes CHROMOSOMAL MUTATIONS structure number

74. Homologous chromosomes ________________ during MEIOSIS = _________________________ One cell gets 2 copies of the chromosome the other cell gets none. NONDISJUNCTION fail to separate

75. Nondisjunction

76. Since it happens to a sperm or egg, the new baby can end up with _____________ of a chromosome = __________________ OR only ___________ of a chromosome = ___________________ TRISOMY MONOSOMY 3 copies one copy

77. Human Abnormalities caused by Non-Disjunction __________________ __________________ __________________ Down syndrome Klinefelter syndrome Turner syndrome

78. Down syndrome (= ____________) TRISOMY 21

79. Down syndrome (Trisomy 21) 1 in 800 births Similar facial features Slanted eyes Protruding tongue

80. Down syndrome (Trisomy 21) Simian line on palm

81. Down syndrome (Trisomy 21) Most common chromosomal abnormality 50% have heart defects that need surgery to repair Mild to severe mental retardation Increases susceptibility to many diseases Risk of having a child with Down syndrome increases with age of mom

82. Down syndrome (Trisomy 21) Risk of having a child with Down syndrome related to age of mom More common in women UNDER 16 or OVER 35 Cells that make eggs start meiosis in embryo Stop in PROPHASE I (synapsis) One egg restarts & finishs division each month So an egg released at age 40 has been in synapsis for 40 years... chromosomes more likely to “stick”

83. Turner syndrome

84. Turner syndrome ____ 1 in 5000 births Females have only one X chromosome Small size Slightly decreased intelligence 35% have heart abnormalities Hearing loss common Broad chest Reproductive organs don’t develop at puberty Can’t have children http://medgen.genetics.utah.edu/photographs/diseases/high/611.gif XO

85. Klinefelter syndrome XXy

86. Klinefelter syndrome 1 in 1000 births Males have extra X chromosomes (Can be XXy, XXXy, or XXXXy) Average to slight decrease in intelligence Small testes/can’t have children Usually not discovered until puberty when don’t mature like peers

87. If having extra chromosomes causes genetic problems, how come having two X chromosomes in females and one X in males is not a problem?

88. X-chromosome Inactivation In female cells ______ chromosome is randomly ________________ It condenses and forms a dense region in the nucleus called a _____________ BARR BODY http://fig.cox.miami.edu/~cmallery/150/gene/barr.htm ONE X SWITCHED OFF

89. In some female cells the X with the allele for orange spots is switched off and in some cells the X with the allele for black spots is switched off, so cat has different colored spots. CAT COLOR In cats, a gene that controls the _____________ is carried on the ____________________ X chromosome http://www.islandstrolling.com/mainland/peloponnes/photo/mystra_cat_white_orange_black.jpg SPOT COLOR See a video

90. _________ cats have only one X chromosome, so they can only have ____________ of spots! CAT COLOR Male one color http://ascensionparish.net/forum/messages/14/2493.jpg THINK ABOUT IT? How many colors of spots could a male cat with Klinefelter syndrome have?

91. Detecting Genetic Disease Genetic Screening – examination of a person’s genetic makeup involving karyotypes, blood tests for certain proteins, or direct tests of DNA –200 genetic disorders can be detected in the fetus –Amniocentesis – removal of amniotic fluid from the sac that surrounds the fetus between the 14 th and 16 th week of pregnancy –Chorionic villi sampling – sample of cells derived between the 8 th and 10 th week from the zygote - cells grow between the mother’s uterus and the placenta; cells chromosomes, and proteins analyzed

92. Detecting Genetic Disease –Chorionic villi sampling – CVS can help identify chromosomal problems such as Down syndrome or other genetic diseases such as cystic fibrosis, Tay- Sachs disease and sickle cell anemia. CVS is considered to be 98% accurate in the diagnosis of chromosomal defects, such as Down syndrome.Down syndromecystic fibrosissickle cell anemia