Chapter 2 Mendels Lay Basic rincipley'ofunhertance 急尔遗传湖 积
Chapter 2 Mendel’s Law: The Basic Principles of Inheritance 第二章 孟德尔遗传规律
Monohybrid crosses: The principle of segregation Dihybrid crosses: The principle of independent assortment Extensions of mendel's laws > Forrnulaing and tesing gene的c ypoineses > Mendelian Principles in Animals
➢Monohybrid crosses: The principle of segregation ➢Dihybrid crosses: The principle of independent assortment ➢Extensions of Mendel’s laws ➢Formulating and testing genetic hypotheses ➢Mendelian Principles in Animals
Menders study of钟y量 His parents were farmer/in Moravia, thera the Hapsberg Empire -in Centre Europe 雷 At the age 2I, Mendel left the farrn ard entered Catholic monastery in the crty of Bri DiM In 84The was. ordairecF priest taught the local highe Itak ng time out belween 1951 and 1953,to-study iVershsywomyhenras FAfter returning to BriinnLeareseimedFhris-life as a teaching y-In 1865, Mendle presented Bisrestilts before the local Natural History Society
Mendel’s study of heredity ✓ His parents were farmers in Moravia, then a part of the Hapsberg Empire in Central Europe ✓ At the age of 21, Mendel left the farm and entered a Catholic monastery in the city of Brünn ✓ In 1847 he was ordained a priest, taught at the local high school, taking time out between 1951 and 1953 to study at the University of Vienna ✓ After returning to Brünn, he resumed his life as a teaching monk and began his experiment with garden pea ✓ In 1865, Mendel presented his results before the local Natural History Society
孟德尔选择豌豆作为杂交材料的原因 豌豆的形状和色泽极易区分和分析;豌豆 为自花授粉植物,易于杂交
孟德尔选择豌豆作为杂交材料的原因 豌豆的形状和色泽极易区分和分析；豌豆 为自花授粉植物，易于杂交
The garden pea One peculiarity of pea reproduction is that the petals of the flower close down tightly, preventing pollen grains from entering or leaving. This enforces a system of self-fertilization Each variety of peas are distinguished by a particular characteristic. Mendel's focus on these singular differences between pea strains allowed him to study the inheritance of one trait at a time Mendel succeeded beeause he focused his attention on contrasting differences between plants
The garden pea One peculiarity of pea reproduction is that the petals of the flower close down tightly, preventing pollen grains from entering or leaving. This enforces a system of self-fertilization Each variety of peas are distinguished by a particular characteristic. Mendel’s focus on these singular differences between pea strains allowed him to study the inheritance of one trait at a time. Mendel succeeded because he focused his attention on contrasting differences between plants
孟德尔试验成功的原因 前人的试验有两个问题:没有对杂交子 代按性状分类计数和没有运用统计分析 孟德尔成功之处在于:运用假说-推理方 法,注意实验材料的选择,引入群体分 析和数量统计分析
孟德尔试验成功的原因 • 前人的试验有两个问题：没有对杂交子 代按性状分类计数和没有运用统计分析 • 孟德尔成功之处在于：运用假说-推理方 法，注意实验材料的选择，引入群体分 析和数量统计分析
Monohybrid crosses: The principle of segregation TalPand dwarf varieties are 分离定律 crossed-fertilized All progeny e tall Homozygous HOmozygous The hynd All Fl offspring progeny are efffermized are heterozygous and purple color TAng Ratio or g 2g de the F asprin will show three phenotypes in a 1: 2: 1 ratio
Monohybrid crosses: The principle of segregation 分离定律 Homozygous×Homozygous All F1 offspring are heterozygous and purple color. Ratio of 1:2:1 Tall and dwarf varieties are crossed-fertilized All progeny are tall. Tall 3: Dwarf 1
Mendels explanation for segregation对分离现象的解 Inheritant traits are determined by genes 遗传性状由基圆决 There are a pair of genes controlling a trait in a ce体细胞中有两个基因控制一个性状 A pair of gene segregate frorn each other during the formalion of gametes在性綢胞形咸中 成对的國彼踹分离 > Each gamete carries an allele每个性细胞含一个 基因 The cornoingiion of garnered is randorn 性绸洄的绪合完全机
Mendel’s explanation for segregation 对分离现象的解释 ➢ Inheritant traits are determined by genes 遗传性状由基因决定 ➢ There are a pair of genes controlling a trait in a cell体细胞中有两个基因控制一个性状 ➢ A pair of gene segregate from each other during the formation of gametes 在性细胞形成中 成对的基因彼此分离 ➢ Each gamete carries an allele 每个性细胞含一个 基因 ➢ The combination of gametes is random 性细胞的结合完全随机
Interpretation图示解释 AA×aa Gametes A a eggs 1/2A 12a sperm 12A1/4AA1/4Aa 12a1/4AA1/4aa IAA: 2Aa: laa 3
P AA×aa Gametes A a F1 Aa Eggs 1/2 A 1/2 a sperm 1/2 A 1/4 AA 1/4 Aa 1/2 a 1/4 AA 1/4 aa 1AA：2Aa：1aa 3 ： 1 Interpretation 图示解释
Glossary o Dominance: a condition in which one member of allele pair is manifested to the exclusion of the other o Recessive: a term applied to one member of an allelic lacking the ability to manifest itself when the other or dominant member is present o Genes and allele. o Homozygous and heterozygous o Genotype and phenotype o parental
Glossary o Dominance: A condition in which one member of allele pair is manifested to the exclusion of the other o Recessive: A term applied to one member of an allelic lacking the ability to manifest itself when the other or dominant member is present o Genes and allele: o Homozygous and heterozygous o Genotype and phenotype o parental