Unit 8 genetics powerpoint (revised 2006)

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Unit 8 genetics powerpoint (revised 2006)

  1. 1. What is genetics?
  2. 2. HEREDITY The study of...
  3. 3. What is HEREDITY? The passing of traits from parent to offspring.
  4. 4. Why do we care about genetics?
  5. 5. <ul><li>Genetics has determined the history and will determine the future of all living things. </li></ul><ul><li>We are in the “Age of Genetics” </li></ul>Stem cell research Fertility drugs Genetic Engeneering
  6. 6. Chromosomes, Genes, Traits and Alleles
  7. 7. Chromosomes are strands of ______that carry our __________ __________ DNA GENETIC TRAITS
  8. 8. Chromosomes <ul><li>Chromosomes are made up of many GENES. </li></ul><ul><li>Genes are </li></ul><ul><li>instructions for </li></ul><ul><li>the TRAITS </li></ul><ul><li>you have. </li></ul>
  9. 9. VISUALIZE the GENES EACH X is a chromosome. On the X are little marks. Each mark is a gene. Where are they? IN THE NUCLEUS
  10. 10. TEST YOURSELF <ul><li>1. DNA is held in what part of the cell? </li></ul><ul><li>2. DNA is grouped into sets of what in each cell? </li></ul><ul><li>FACT: These 23 sets of chromosomes are called your genome! </li></ul><ul><li>3. Each chromosome contains DNA grouped into something called _________ which carries information that tells the cell to make a unique protein that will perform a special function. </li></ul><ul><li>Genes are instructions for the ___________ you have. </li></ul>NUCLEUS CHROMOSOMES GENES TRAITS
  11. 11. In your note packet, write down examples of some human traits. <ul><li>Example: Eye color is a human trait </li></ul>
  12. 12. Homologous chromosomes, alleles and more
  13. 13. Remember what homologous chromosomes are? THEY ARE: A pair of chromosomes containing the same gene sequences , each derived from one parent . The chromosomes tend to pair during meiosis.
  14. 14. Homologous Chromosomes <ul><li>Each homologous chromosome has the same traits on it, but they can be for different alleles . </li></ul><ul><li>WHAT IN THE WORLD IS AN ALLELE? </li></ul>
  15. 15. ALLELE <ul><li>Possible options for one trait </li></ul><ul><li>EXAMPLE: brown eye color or blue eye color </li></ul>
  16. 16. Using the list of human traits you have already made in your notes, list possible alleles for the traits. <ul><li>Example: The trait is eye color </li></ul><ul><ul><li>Possible alleles are brown and blue </li></ul></ul>
  17. 17. The homologous chromosomes below have the same traits on them, but they are for two different alleles . Both chromosomes in the homologous pair contain the trait for hair texture, but one carries the allele for curly hair & the other one carries the allele for straight hair .
  18. 18.                                      
  19. 19. GENE INTERACTION….
  20. 20. <ul><li>What the organism looks like . </li></ul>Phenotype
  21. 21. <ul><li>The actual genes (alleles) the organism has. </li></ul>Genotype <ul><li>We use big and </li></ul><ul><li>small letters to </li></ul><ul><li>symbolize genes </li></ul>
  22. 22. When figuring out what the PHENOTYPE will be when a certain GENOTYPE is present, you need to find out the _____________ of each allele. INTERACTION
  23. 23. How do alleles interact with each other?
  24. 24. 3 Gene Interactions <ul><li>Dominant vs. Recessive </li></ul><ul><li>Incomplete Dominance </li></ul><ul><li>Codominance </li></ul>
  25. 25. Dominant vs. Recessive
  26. 26. Dominant/Recessive interactions <ul><li>The dominant allele will “cover up” the recessive allele. </li></ul>
  27. 27. Incomplete Dominance interactions <ul><li>When the 2 different alleles are present, the phenotype will look like a BLENDING of the two. </li></ul>
  28. 28. INCOMPLETE DOMINANCE A trick to remember this is “ IN ” your “ blender ” we make a shake. ‘ IN’COMPLETE=‘BLENDING’
  29. 29. Codominance <ul><li>Both alleles act as dominant, so you will get a result with both alleles shown fully . </li></ul>
  30. 30. CODOMINANCE REMEMBERED: CO- BOTH Think of Co-ed (means BOTH boys and girls) Codominance means BOTH traits show
  31. 31. Gene interaction questions (These genes are not actually real, they are for example only) <ul><li>A girl inherits a long eyelash gene from her father and a short eyelash gene from her mother. The short eyelash gene is dominant and the long eyelash gene is recessive . </li></ul>What is the length of the girl’s eyelashes? Her eyelashes are short
  32. 32. Gene interaction questions (These genes are not actually real, they are for example only) <ul><li>The interaction of genes for height of the Scar Barked Fast Sapping Evergreen Tree show incomplete dominance . </li></ul>A tall tree is crossed with a short tree, what will the height of the new tree be? Medium height
  33. 33. Gene interaction questions (These genes are not actually real, they are for example only) <ul><li>The interaction of genes for height of the Scar Barked Fast Sapping Evergreen Tree show incomplete dominance . </li></ul>Another question, a short tree is crossed with another short tree, what will the height of the new tree be? Short height
  34. 34. Gene interaction questions (These genes are not actually real, they are for example only) <ul><li>The genes for fur design of Patagonia Panthers are codominant. The 2 possible designs for fur are spotted and striped. </li></ul>A spotted panther is mated with a striped panther. What will the fur design of the baby panther be? Spotted with stripes
  35. 35. Heredity and Genotype http://www.frogstar.com/wav/displaywav.asp?fil=shirley.wav
  36. 36. Look at these cells <ul><li>Which is haploid? </li></ul><ul><li>Which is diploid? </li></ul><ul><li>Which is a body cell? Which is a sperm or egg cell? </li></ul>B A B A
  37. 37. In each of your body cells, how many genes do you have for 1 specific trait? 2 Why? There is one gene on each of the homologous pairs. You got one gene from your mom and one gene from your dad .
  38. 38. Since egg and sperm cells are haploid, how many genes do you have for each trait in an egg? In a sperm? <ul><li>The egg and sperm both have one gene for each trait . </li></ul><ul><li>The homologous pairs were separated during meiosis. </li></ul>1 1
  39. 39. Remember: Meiosis only occurs in __________________. SEX CELLS SEX JUST KIDDING! NO SEX FOR SALE!
  40. 40. The homologous pairs were separated during meiosis. How and when are homologous pairs separated in meiosis in order to make a sperm or an egg?
  41. 41. Metaphase I: How are the homologous chromosomes lined up? In metaphase I of meiosis, homologous pairs are lined up so the homologous pairs are next to one another.
  42. 42. Anaphase I: How are homologous chromosomes separated? Homologous pairs are separated in Anaphase I of meiosis.
  43. 43. At the end of meiosis I, the homologous chromosomes have been separated, the cells are now haploid.
  44. 44. The homologous pairs are split up randomly, so we don’t know which particular chromosome of each pair will be found in each cell. Law of Independent Assortment http://www.frogstar.com/wav/displaywav.asp?fil=bb-alive.wav The alleles for a trait separate when gametes are formed. These allele pairs are then randomly united at fertilization.
  45. 45. Review Quiz…
  46. 46. Where did you get each of your chromosomes? <ul><li>Half from your mother </li></ul><ul><li>Half from your father </li></ul>
  47. 47. How many genes for each trait do you have in each BODY cell? <ul><li>2 genes </li></ul>
  48. 48. How many genes for each trait do you have in each SPERM cell? 1 Gene for each trait WHY? Sperm are haploid
  49. 49. How many genes for each trait do you have in an EGG cell? 1 Gene for each trait Because eggs are haploid
  50. 50. When a sperm fertilizes an egg, how many genes for each trait will the baby have? It has two genes for each trait. The baby will be diploid
  51. 51. Karyotype : All of an organism’s chromosomes are lined up with homologous pairs being placed next to one another. Chromosomes #23 are sex cells.
  52. 52. A Bit ‘O’ Genetic History... <ul><li>THE STUDY OF GENETICS </li></ul>
  53. 53. The Father of Genetics Gregor Mendel and His Peas
  54. 54. Mendel and His Peas <ul><li>He used pea plants because: </li></ul><ul><li>Unlike animals, they could not move </li></ul><ul><li>Easier to test MANY plants whereas animals sometimes take up more space and require more maintenance </li></ul><ul><li>What else…. </li></ul>Why did he use pea plants and not animals? Discuss…
  55. 55. What are 5 traits he was looking at and what were the 2 possible alleles for each? TEXTURE Seed Color Pod Color Flower color
  56. 56. When the gene interaction is dominant vs. recessive, you need to know the genotypes of the parents in order to accurately figure out what the possibilities are for their children.
  57. 57. Remember …. <ul><li>PHENOTYPE = What the organism looks like. </li></ul><ul><li>GENOTYPE = The genes (alleles) the organism has. </li></ul>
  58. 58. Example: A species of bird has 2 possible alleles for wing color, red and green . The alleles have a dominant vs. recessive interaction with one another. The red allele is dominant over the green allele. We will be representing the red allele as “ R ” and the green allele as “ r ”.
  59. 59. Red allele ( R ) is dominant over Green allele ( r ) <ul><li>A bird has a red wing, what are the possible genotypes for red wing? </li></ul>The bird could have the genoytpe “ R R ”or “ R r ” • In genetics, there is a special term to describe both of these combinations. If the 2 alleles are the same ( RR ) or ( rr ) they are said to be homozygous. “Homo” means “same” If the 2 alleles are different ( R r ) they are called heterozygous. “Hetero” means “different”
  60. 60. <ul><li>Lemurs have 2 possible alleles for tail appearance, fluffy and straight. </li></ul><ul><li>Fluffy (F) is dominant over straight (f). </li></ul>Quiz yourself The phenotype of lemur #1 is fluffy tail The phenotype of lemur #2 is straight tail • What are the possible genotypes for lemur #1? • What are the possible genotypes for lemur #2? Lemur #1: FF (homozygous) or Ff (heterozygous) Lemur #2: ff (homozygous)
  61. 61. A man inherited from his mother, a chromosome which has the blue eye color allele on it. He also inherited from his father, the chromosome which has the brown eye color allele on it. <ul><li>The man has a child, which eye color allele will the child inherit, blue or brown? </li></ul>Answer: It is impossible to tell, it could be either the Brown or the blue. What is his genotype? Bb - heterozygous
  62. 62. Did you get those? You are smart!
  63. 63. Predicting possible outcomes <ul><li>Punnet squares </li></ul><ul><ul><li>Possibilities for genetic combinations </li></ul></ul>
  64. 64. Punnet square problem #1 A man who is heterozygous for brown eyes has a baby with a woman who is heterozygous for brown eyes. What are the possible phenotypes and genotypes their children could have? Do a Punnet square The brown eye allele is dominant over blue. 1. Brown is dominant over blue 2. Both parent’s phenotypes are brown. 3. Both parents are heterozygous - Bb
  65. 65. Punnet Square Mother’s and father’s genotypes are both Bb Possible egg genes are B or b Possible sperm genes are B or b B b B b Possible genotypes for offspring are: BB Bb Bb bb BB, Bb, bb Possible phenotypes are: Brown and blue What are the chances of Getting a brown eyed child? A blue eyed child? The ratio is 3:1 brown to blue. 75% chance of brown and 25% chance of blue
  66. 66. Punnet Square Mother’s and father’s genotypes are both Bb Possible egg genes are B or b Possible sperm genes are B or b B b B b Possible genotypes for offspring are: BB Bb Bb bb BB, Bb, bb Possible phenotypes are: Brown and blue What are the genotypic ratios? The ratio is 1:2:1 1 BB 2 Bb 1 bb
  67. 67. Punnet Square Question #2 brown and yellow 2:2 --> 1:1 A female duck with yellow feet mates with a male duck who is heterozygous for brown feet. What are the possible feet colors for the chicks? Brown is dominant over yellow. Mother duck’s genotype is: bb Father duck’s genotype is: Bb b b B b Bb bb Bb bb Possible phenotypes are: Possible genotypes are: Bb and bb 2:2 --> 1:1 Going further….
  68. 68. Do some examples in the class notes
  69. 69. Punnet Squares With 2 Traits Mother’s genotype : Bbll Father’s genotype : bbLl A woman who is heterozygous for brown eyes and has small toes marries a man who has blue eyes and heterozygous for large toes. What are the possible genotypes and phenotypes of their children? Brown eyes are dominant over blue Large toes are dominant over small toes
  70. 70. To form the possible egg and sperm… Think: First with third, first with fourth Second with third, second with fourth Bbll Bl Bl bl bl
  71. 71. Punnet Squares With 2 Traits Mother’s genotype: B b l l Father’s genotype: b b L l Possible eggs: Bl, Bl, bl, bl Possible sperm: bL, bl, bL, bl Bl Bl bl bl bL bl bL bl BbLl BbLl Bbll Bbll BbLl BbLl Bbll Bbll bbLl bbLl bbll bbll bbLl bbLl bbll bbll
  72. 72. Punnet Squares With 2 Traits Mother’s genotype: B b l l Father’s genotype: b b L l Bl Bl bl bl bL bl bL bl BbLl BbLl Bbll Bbll BbLl BbLl Bbll Bbll bbLl bbLl bbll bbll bbLl bbLl bbll bbll Possible genotypes: BbLl Bbll bbLl bbll 1:1:1:1 Ratio Possible phenotypes: Brown eyes/large toes Brown eyes/small toes blue eyes/large toes blue eyes/small toes 1:1:1:1 Ratio
  73. 73. Punnet Squares 2 Traits - Difficult A female wavy fur spaniel with heterozygous brown paws is mated with a male wavy fur spaniel with heterozygous brown paws. • What are the possible genotypes and ratios? • What are the possible phenotypes and ratios? Straight and curly fur show incomplete dominance . Brown paws are dominant over white paws. Female’s genotype is: Male’s genotype is: csBb csBb
  74. 74. Punnet Squares 2 Traits - Difficult Female’s genotype is: csBb Male’s genotype is: csBb Possible genes in eggs: cB, cb, sB, sb Possible genes in sperm: cB, cb, sB, sb cB cb sB sb cB cb sB sb ccBB ccBb csBB csBb ccBb ccbb csBb csbb csBB csBb ssBB ssBb csBb csbb ssBb ssbb
  75. 75. Punnet Squares 2 Traits, #2 Genotypes: cB cb sB sb cB cb sB sb ccBb csBB csBb ccBb ccbb csBb csbb csBB csBb ssBB ssBb csBb csbb ssBb ssbb ccBB ccBb csBB csBb ccbb csbb ssBB ssBb ssbb csBB 2 csBb 4 ccbb 1 csbb 2 ssBB 1 ssBb 2 ssbb 1 ccBB 1 ccBb 2 Genotype ratio: ccBB 1:2:2:4:1:2:1:2:1
  76. 76. Punnet Squares 2 Traits, #2 Genotypes: CCBB CCBb CSBB CSBb CCbb CSbb SSBB SSBb SSbb CSBB 2 CSBb 4 CCbb 1 CSbb 2 SSBB 1 SSBb 2 SSbb 1 CCBB 1 CCBb 2 Genotype ratio: Phenotype ratio: Curly/Brown 3 Wavy/Brown 6 Curly/white 1 Wavy/white 2 Straight/Brown 3 Straight/white 1 3 : 6 : 1 : 2 : 3 : 1
  77. 77. Sometimes genes change by accident. It is call a… <ul><li>Mutations </li></ul>OOPS!
  78. 78. There are 3 possible outcomes when a mutation occurs...
  79. 79. 1. Lethal <ul><ul><li>It kills the organism before birth or later. </li></ul></ul>
  80. 80. 2. Negative Effect <ul><ul><li>Ranging from minor  severe </li></ul></ul><ul><ul><li>None at all </li></ul></ul>
  81. 81. 3. Positive Effect <ul><ul><li>Very rarely happens this way </li></ul></ul><ul><ul><li>Makes organism better adapted </li></ul></ul><ul><ul><li>2 examples are… </li></ul></ul>
  82. 82. Example #1: Camouflage <ul><li>A mutation occurred, and actually helped these organism survive! </li></ul><ul><li>Advantage increases an animal's chances of survival. </li></ul><ul><li>Chances of reproducing and passing on the trait. </li></ul>
  83. 83. Example #2: Sickle Cell Anemia <ul><li>Mutation that happened in malaria-prone regions. </li></ul><ul><li>More likely to survive malaria epidemics. </li></ul><ul><li>They survived when others did not, this allowed the trait to be passed down through generations. </li></ul>
  84. 84. Types of Mutations Type A: Mutations that occur during Meiosis Type B: Mutations that occur during DNA replication
  85. 85. Type A: Mutations That Occur During Meiosis
  86. 86. Mutations That Occur During Meiosis Examples: Duplication Mutation Deletion Mutation Inversion Mutation Translocation Nondisjunction
  87. 87. Type A: Mutations That Occur During Meiosis During Prophase Crossing over done incorrectly
  88. 88. Type A: Mutations That Occur During Meiosis 47 During Anaphase II Chromatids separating incorrectly 24 23
  89. 89. Type B: POINT MUTATIONS <ul><li>Mutations that occur during DNA replication. </li></ul>
  90. 90. Mutations that arise from nucleotide bases having errors are called POINT MUTATIONS
  91. 91. POINT MUTATIONS ARE Base Pair Addition Base Pair Deletion Base Pair Substitution
  92. 92. Let’s see if you can figure it out! Activity Fill in your pages
  93. 93. What causes mutations?
  94. 94. MUTATION CAUSES <ul><li>Natural Causes- mistakes in the DNA </li></ul><ul><li>IN THE CLEANING SUPPLIES YOU USE </li></ul>2. Environmental Factors…Mutagens <ul><li>IN THE TOBACCO THAT PEOPLE USE </li></ul><ul><li>IN THE FOOD YOU EAT </li></ul>3. UV-Rays & X-Rays
  95. 95. How many people do you know who smoke? 1 out of every 3 tobacco users will die from a tobacco related illness. Think for a second and count them .
  96. 96. Tobacco Stinks Sucks Smells And KILLS
  97. 97. In the dentist’s office, why do they place a lead apron over a person’s lap? They want to protect the reproductive organs. If a mutation occurs in the reproductive organs, it may end up disfiguring a future child, or worse.
  98. 98. 4. Heavy Metals <ul><li>Lead </li></ul><ul><li>Mercury </li></ul><ul><li>Cadmium </li></ul><ul><li>(Not heavy metal like Metallica) </li></ul>MUTATION CAUSES CONT…
  99. 99. 5. UV Rays <ul><li>a. Holes in the ozone layer </li></ul>b. Tanning beds
  100. 100. 6. Nuclear radiation
  101. 101. Things that cause mutations are called Mutagens
  102. 102. Exposure to mutagens can cause mutations in 2 general areas. <ul><li>Mutations in the sex cells, eggs and sperm. </li></ul><ul><li>What do you think these mutations might lead to? </li></ul>2. Mutations in the other cells of the body. What do you think these might lead to? BIRTH DEFECTS OR DEATH CANCER
  103. 103. If you do not mind… <ul><li>Please stand up if you or someone in your immediate family has had cancer. </li></ul><ul><li>Please stand up if someone you are related to has had cancer. </li></ul><ul><li>Please stand up if you know someone personally who has had cancer. </li></ul><ul><li>Please stand up if you have a friend who is related to someone who has had cancer. </li></ul>
  104. 104. So what exactly is this ugly disease?
  105. 105. Cancer is a disease where cells begin to divide by mitosis uncontrollably. A mutation(s) can occur in one single cell, and by the process of mitosis it can grow into tens of thousands or more cells in a relatively short period of time.
  106. 106. What forms when a cell has undergone mitosis uncontrollably for a while in one central spot? A Tumor
  107. 107. Cancer Treatments 1. Surgerical removal of cancer
  108. 108. 2. Chemotherapy- Treatment with drugs that kill cancer cells or make them less active. 3. Radiation- uses high-energy waves, such as X-rays (invisible waves that can pass through most parts of the body), to damage and destroy cancer cells.
  109. 109. 4. Another option is a STEM CELL TRANPLANT Radiation and anti-cancer drugs are very good at destroying cancer cells, but unfortunately they also destroy healthy cells. http://www.leapingmedia.com/Media/TransplantAnimation.mov
  110. 110. THE HUMAN SYSTEM <ul><li>44 “regular” chromosomes, called autosomes </li></ul><ul><li>2 sex chromosomes (23rd Pair) </li></ul><ul><ul><li>X </li></ul></ul><ul><ul><li>Y </li></ul></ul><ul><ul><li>THAT MEANS HUMANS HAVE A TOTAL OF ____ CHROMOSOMES! </li></ul></ul>
  111. 111. What can you tell me about this person by looking at their karyotype? <ul><li>He is Male </li></ul>MALES are XY
  112. 112. What can you tell me about this person by looking at their karyotype? <ul><li>She is female </li></ul>Females are XX
  113. 113. What about this person? <ul><li>Male with Klinefelter Syndrome. </li></ul><ul><li>What kind of mutation caused this? </li></ul>Nondisjunction. He is trisomy for the sex chromosomes.
  114. 114. What about this person? <ul><li>Female with Turner Syndrome. </li></ul><ul><li>What kind of mutation caused this? </li></ul>Nondisjunction. She is monosomy for the X sex chromosome.
  115. 115. Sex linked genes <ul><li>The X and Y chromosomes do not carry the same genes on them. </li></ul><ul><li>In fact, the Y chromosome does not carry many useful genes at all. </li></ul><ul><li>When deciding what traits a person carries on their sex chromosomes, it is often useful to consider males as if they are actually missing a chromosome because there are very few useful genes located on the Y chromosome. (Sorry Guys) </li></ul>
  116. 116. Sex Linked Genes When we refer to a “sex linked gene”, it means that the gene is located on a sex chromosome . Very few traits are found on the Y chromosome, so when we talk about sex linked genes, you can assume the gene is located on the X chromosome .
  117. 117. Sex Linked Punnet Squares When doing Punnet squares with sex linked genes, you have to include the sex chromosome as well as the gene it carries. To show that an X chromosome carries a gene, you put the letter as a superscript of the X. X B X b would indicate a female who is heterozygous for the trait “B”
  118. 118. Color blindness is an X linked gene A woman who is a carrier (heterozygous) of the color blind gene has children with a man who is not colorblind. Colorblind (c) is a recessive gene to the dominant color seeing gene (C). What are the chances that they could have a son who is colorblind? A daughter who is color blind? Genotype of the mother is: Genotype of the father is: X C X c X C Y
  119. 119. Color blindness is an X linked gene Possible genotype for the egg: Possible genotype for sperm: Genotype of the mother is: Genotype of the father is: X C X c X C Y X C or Y X C X C X c Y X C or X c
  120. 120. Color blindness is an X linked gene Possible genotype for the egg: Possible genotype for sperm: X C or Y X C X C X c Y X C or X c X C X C X C Y Y X c X C X c The chance that they will have a colorblind SON is 50% The chance that they will have a colorblind DAUGHTER is 0% (but 50% for a carrier)
  121. 121. Color blindness is an X linked gene A woman who is homozygous for color seeing has a child with a man who is colorblind. What are the chances that his daughter will be colorblind? What are the chances that his son will be colorblind? Colorblind (c) is a recessive gene to the dominant color seeing gene (C). Woman’s genotype: Man’s genotype: X C X C X c Y
  122. 122. Color blindness is an X linked gene There is 0% chance that they will have a color blind boy or girl. But 100% chance That their daughters would all be carriers. Woman’s genotype: Man’s genotype: X C X C X c Y X C X c X C Y X C X c X C Y Y X c X C X C
  123. 123. Color Blindness Test What number do you see? Okay, so this is the one that everyone is supposed to be able to see!
  124. 124. Red/Green Color Blindness Test What number do you see? 7
  125. 125. Red/Green Color Blindness Test What number do you see? 2
  126. 126. Male patterned baldness is X linked One of the science teachers above has 2 children, a boy and a girl. His wife is heterozygous for the male patterned baldness gene. What are the possibilities that his son or daughter will have male patterned baldness? (Male patterned baldness is a recessive allele)
  127. 127. Results X H X h X h Y H = Hair h = bald X H X H X h X h X h X h Y Y 50% chance son will bald 50% chance daughter could bald Testosterone is needed to “ turn on” this balding gene, so it is very unlikely that a girl will go bald even if she is homozygous for this balding gene.
  128. 128. If a young man wants to get some idea if he may have male patterned baldness, who should he look at, his father or his mother’s father? Why?
  129. 129. Because the male patterned baldness is sex linked, he did not receive the gene from his father, he got it from his mother. Looking at the father’s side of the family is useless because he got his Y chromosome from his dad, not an X.
  130. 130. Pedigree Pedigrees are symbolic representations of a family and the alleles they have. When creating a pedigree, this symbol means the person is male. When creating a pedigree, this symbol means the person is female. When creating a pedigree, this symbol means the person is of unknown gender. This is often used if in the history of family, a child died at birth and the gender of the child is not known.
  131. 131. Pedigree The horizontal line connecting this man and woman means that they are married. The same symbol as above but having a diagonal line through the marriage line means that the couple is divorced. This collection of symbols means that the man is divorced and remarried. A symbol with a diagonal line through it means that The person is no longer living.
  132. 132. Pedigree What collection of symbols could show a couple who is married and has son and a daughter.
  133. 133. Pedigree A couple is married, they have A son and a daughter. Their son is married and he and his wife have a son. Get the idea?
  134. 134. Pedigree Representing genetic traits within a pedigree. The symbol colored in means that the person is homozygous for the allele. The symbol half colored in means that the person is heterozygous for the allele. The symbol not colored in means that the person does not have the allele.
  135. 135. Pedigree for the blue eye allele A pedigree for a brown eye allele The brown eye allele is dominant In this family,who has brown eyes? Everyone except This woman.
  136. 136. Quiz Time YOU Who is this? Sister
  137. 137. Quiz Time YOU Who is this? Maternal grandfather
  138. 138. Quiz Time YOU Who is this? half sister
  139. 139. Quiz Time YOU What information do we know about your grandmother? She has passed away
  140. 140. Quiz Time YOU Who is this? Aunt
  141. 141. Quiz Time YOU Pedigree for the big nose allele, it is recessive. Who has a big nose? You and your aunt
  142. 142. Quiz Time YOU Pedigree for the big nose allele, it is recessive. What is the genotype of your cousin?
  143. 143. Quiz Time YOU Pedigree for the big nose allele, it is recessive. What is the genotype of your cousin? Heterozygous
  144. 144. Paternity tests <ul><li>It is possible to tell if a certain man is the father of a baby by comparing the baby’s DNA to his and the baby’s mother. </li></ul>• Since the DNA the baby has came from it’s mother and father, the DNA should all be accounted for between the 2 parents.
  145. 145. Paternity Test - Match the DNA
  146. 146. Paternity Test - Match the DNA
  147. 147. Paternity Test - Match the DNA
  148. 148. DNA fingerprinting <ul><li>DNA fingerprinting is quite similar to a paternity test, but the person’s DNA is compared to DNA found at the crime scene. If the chromosome fragments line up, it positively IDs the person as being part of the crime. </li></ul>
  149. 149. THE END

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