14Allele Member of a paired gene Represented by a single letter One allele comes from each parentRepresented by a single letter
15Dominant & Recessive Alleles Dominant alleles are expressedRecessive alleles are not expressed in the presence of a dominant alleleRecessive alleles are only expressed if both recessive alleles are present
16Gene A unit of heredity that controls the development of one trait Made of DNAMost genes are composed of two alleles
31AA Aa aa Genotypes Phenotypes Probability 1 AA, 2Aa, 1aa 3 Normal 1 AbinoProbability25% for albinism
32A man & woman are both carriers (heterozygous) for PKU disease A man & woman are both carriers (heterozygous) for PKU disease. What is the chance their children will inherit PKU disease?
33PP = NormalPp = Normal (carrier)pp = PKU diseasePpPPPpppPp
34PP Pp pp Genotypes Phenotypes Probability 1 PP, 2Pp, 1pp 3 Normal 1 PKU diseaseProbability25% for PKU disease
35A man with sickle cell anemia marries a woman who is a carrier A man with sickle cell anemia marries a woman who is a carrier. What is the chance their children will inherit sickle cell anemia?
36SS = NormalSs = Normal (carrier)ss = Sickle CellSssSssss
37Genotypes ss Ss Phenotypes Probability 2 Ss, 2ss 2 Normal (carriers) 2 Sickle cellProbability50% for Sickle cell
38Dwarfism DD = Dwarfism Dd = Dwarfism dd = Normal height Dwarfism = D Dwarf Band
39A man with heterozygous dwarfism marries a woman who has normal height A man with heterozygous dwarfism marries a woman who has normal height. What is the chance their children will inherit dwarfism? Dwarfism is dominant.
41Genotypes Dd Phenotypes dd Probability 2 Dd, 2dd 2 Normal 2 Dwarfs 50% for Dwarfism
42Law of Independent Assortment The inheritance of one gene does not influence the inheritance of another gene if they are on separate chromosomes.The gene for albinism does not affect the gene for dwarfism
43Dihybrid Cross or Two Traits A heterozygous tall plant that is also heterozygous for yellow seeds is crossed with another plant with the same genotypeTall and yellow seeds are dominant to short and green seeds.
44What gametes can each parent produce? Tall YellowTall YellowTtYyTtYyTYTYTytYtyTytYty
45Match gametes on a Punnent Square TYTytYtyTtYyTTYYTTYyTtYYTTyyTtyyttYYttYyttyy9 Tall-YellowTYTytYty3 Tall-Green3 Short-Yellow1 Short-Green
46A man with blue eyes and normal height marries a woman with heterozygous brown eyes and heterozygous dwarfism. What are the possible phenotypes of their children? Dwarfism & brown eyes are dominant.
47What gametes can each parent produce? Normal height-BlueDwarf-BrownddbbDdBbdbDBDbdBdb