第1章 遗传因子的发现第2节 孟德尔的豌豆杂交实验( 二)Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.实验 现象假说推论验证理论假 说演 绎 法两对相对性状的杂交实验对自由组合 现象的解释设计测交实验测交实验自由组合定律Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.两对相对性状的遗传实验绿色皱粒Px黄色圆粒F1 黄色圆粒F2黄色 圆粒黄色 皱粒绿色 圆粒绿色 皱粒 个体数315101108329331：F2出现新的性状 组合是什么? 为 什么会出现新的 性状组合?黄色和绿色、圆 粒和皱粒何为显 性性状,何为隐性 性状?Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.从数学角度分析,9:3:3:1与3:1能否建立数 学联系,这对理解两对相对性状的遗传结果有什 么启示?对每一对相对性状单独进行分析粒形粒色圆粒种子 315+108=423皱粒种子 101+32=133黄色种子 315+101=416绿色种子 108+32=140圆粒: 皱粒接近3：1黄色：绿色接近3：1(3:1)(3:1)=9:3:3:1Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.对自由组合现象的解释(假说)l豌豆的圆粒和皱粒分别由遗传因 子R、r控制,黄色和绿色分别由遗 传因子Y、y控制。l在产生配子时,每对遗传因子彼此 分离,不同对的遗传因子可以自由 组合。l受精时,雌雄配子的结合是随机的 。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.黄圆绿皱豌豆杂交实验分析图解YRyrYy RrF1配子黄色圆粒YRyryRYr配子yy rrYY RR 黄色圆粒绿色皱粒PEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.YY RRyy rrYy RRYY RrYy RrYy RrYy RrYy RrYy RRYY Rryy RRyy Rryy RrYY rrYy rrYy rrF1配子YRyryRYrYRyryRYr性状表现:9:3:3:1 遗传因子组成共9种:4种纯合子各1/16, 1种双杂合子4/16,4种单杂合子各2/16Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.对自由组合现象解释的验证测交实验Yy RrYy rryy Rryy rrYRyryRYryr配子测交 后代1 : 1 : 1 : 1Yy Rr杂种子一代 yy rr隐性纯合子测交 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.自由组合定律控制不同性状的遗传因 子的分离和组合是互不干扰 的;在形成配子时,决定同一 性状的成对的遗传因子彼此 分离, 决定不同性状的遗传 因子自由组合。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.孟德尔实验方法的启示l孟德尔获得成功的主要原因 1.精心选择实验材料 2.精心设计实验方法(单因子分析) 3.精确的统计分析 4.首创了测交实验Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.孟德尔遗传规律的再发现l几个概念 基因 表现型 基因型 等位基因Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.分枝法在解遗传题中的应用 该法的原理为乘法原理,故常用于解基因自由组合的题。 1.分析亲本产生的生殖细胞种类及比例: 如亲本的基因型为AaBbCc,则其产生的生殖细胞为1/2A1/2a1/2C 1/2c 1/2C 1/2c 1/2C 1/2c 1/2C 1/2c1/2B1/2b1/2B1/2b1/8ABC 1/8ABc 1/8AbC 1/8Abc 1/8aBC 1/8aBc 1/8abC 1/8abc共8种生殖细胞,每种生殖细胞各占1/8.推广: n对等位基因位于n对同源染色体上,则生殖细胞共有2n种, 每种各占1/2n.Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.2.分析杂交后代的基因型、表现型及比例 如:黄圆AaBbX绿圆aaBb,求后代基因型、表现型情况。基因型的种类及数量关系: AaXaa BbXBb 子代基因型1/2Aa1/2aa1/4BB 1/2Bb 1/4bb 1/4BB 1/2Bb 1/4bb1/8AaBB 1/4AaBb 1/8Aabb 1/8aaBB 1/4aaBb 1/8aabb表现型的种类及数量关系: AaXaa BbXBb 子代表现型黄绿圆 皱圆 皱3/8黄圆 1/8黄皱3/8绿圆 1/8绿皱结论:AaBbXaaBb杂交,其后代基因型及其比例为: ;其后代表现型及比例为: Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.怎样求基因型? 1.填空法:已知亲代表现型和后代表现型,求亲代基因型,最适 用此法。 例:鸡毛腿(F)对光腿(f)是显性,豌豆冠(E)对单冠(e)是显 性。现有两只公鸡A、B与两只母鸡C、D。这四只鸡都 是毛腿豌豆冠，它们杂交产生的后代性状表现如下： （1）AXC 毛腿豌豆冠 （2）AXD 毛腿豌豆冠 （3）BXC 毛腿豌豆冠，光腿豌豆冠 （4）BXD 毛腿豌豆冠，毛腿单冠 试求：A、B、C、D的基因型。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspos