Lectures posted online after lecture. Textbook sections and/or pages posted a few days prior to each lecture. CB 14.3 In many instances there is a unique pattern of inheritance. Traits disappear and reappear in new ratios. CB 14.6 Genotype Phenotype Human blood types CB tbl 14.2 AA or AO BB or BO AB OO Looking at the past: If Frank has B blood type, his Dad has A blood type, And his Mom has B blood type... Should Frank be worried? Mom=B blood possible Dad=A blood AA or AO BB or BO genotype s Gametes all B / 50% B and all A / 50% A and 50% O 50% O Frank can be BO ...no worries = B blood We can also predict the future Fig 2.12 Inheritance of blood types Mom = AB Dad = AB Inheritance of blood types Mom = AB Gametes: A or B Dad = AB A or B Inheritance of blood types Mom = AB Gametes: A or B Dad A or B A AA Mom or B AB AB Dad = AB A or B Chance of each phenotype for each offspring BB 25% AA 50% AB 25% BB Testcross: determining dominant/ recessive and zygosity CB 14.7 Sickle-<a href="/keyword/cell-anemia/" >cell anemia</a> is caused by a point mutation CB 5.21 Sickled and normal red blood cells Sickle-<a href="/keyword/cell-anemia/" >cell anemia</a> : A dominant or recessive allele? S=sickle-cell H=normal Mom = HS Dad H or S H HH Mom or S HS HS Dad = HS SS possible offspring 75% Normal 25% Sickle-cell Coincidence of malaria and sickle-<a href="/keyword/cell-anemia/" >cell anemia</a> CB 23.13 Sickle-<a href="/keyword/cell-anemia/" >cell anemia</a> : A dominant or recessive allele? S=sickle-cell H=normal Mom = HS Dad H or S H HH Mom or S HS HS Dad = HS possible offspring Oxygen transport: 75% Normal 25% Sickle-cell SS Malaria resistance: 75% resistant 25% susceptible Variation in Peas Phenotype CB 14.8 Genotype The inheritance of genes on different chromosomes is independen t. CB 14.8 Approximate position of seed color and shape genes in peas Y y Gene for seed color r R Gene for seed shape Chrom. 1/7 Chrom. 7/7 The inheritance of genes on different chromosomes is independent: independent assortment CB 15.2 CB 15.2 meiosis I meiosis II The inheritance of genes on different chromosom es is independent : independent assortment CB 15.2 CB 14.8 CB 14.9 Inheritance can be predicted by probability Probability of a 4= 1/6 Probability of two 4's in a row= 1/6x1/6=1/36 Probability of 3 or 4 = 1/6+1/6= 1/3 &quot;and&quot; multiply &quot;or&quot; add Huntington's Disease D=disease d=normal Neurological disease, symptoms begin around 40 years old. Huntington's Disease D=disease d=normal Mom = dd Dad D or d d Dd Mom or d Dd dd Dad = Dd dd possible offspring 50% Huntington's 50% Normal Two different people: One with Huntington's disease = Dd Hh One without Huntington's disease = dd Hh mate. What is the probability that their offspring will have Huntington's disease and <a href="/keyword/sickle-cell-anemia/" ><a href="/keyword/sickle-cell/" >sickle cell</a> anemia</a> ? (Dd hh) Two people: One with Huntington's disease = Dd Hh One without Huntington's disease = dd Hh mate. What is the probability that their offspring will have Huntington's disease and <a href="/keyword/sickle-cell-anemia/" ><a href="/keyword/sickle-cell/" >sickle cell</a> anemia</a> ? Dd hh Probability of each outcome: Probability of Dd (Ddxdd) = .5 Probability of hh (HhxHh) = .25 Two people: One with Huntington's disease = Dd Hh One without Huntington's disease = dd Hh mate. What is the probability that their offspring will have Huntington's disease and <a href="/keyword/sickle-cell-anemia/" ><a href="/keyword/sickle-cell/" >sickle cell</a> anemia</a> ? Dd hh Probability of each outcome: Probability of Dd (Ddxdd) = .5 Probability of hh (HhxHh) = .25 Multiply both probabilities .25 X.5 = 12.5% chance Dd hh offspring Many traits are coded for by more than one gene. CB 14.11 Eye color: One trait controlled by multiple genes Lectures posted online after lecture. Textbook sections and/or pages posted a few days prior to each lecture.