普通遗传学论文：普通遗传学问题解决的教学设计及行动

第一篇：普通遗传学论文：普通遗传学问题解决的教学设计及行动

普通遗传学论文：普通遗传学问题解决的教学设计及行动研究

【中文摘要】随着社会的发展，对人才培养也提出了新的要求，要求他们具有较好的解决问题的能力、较强的组织与规划能力、良好的交流合作能力。传统教学在对学生的这些能力的培养上显得力不从心，所以研究“问题解决教学”的必要性日益显现。本文对问题解决教学的相关概念进行界定，对问题解决教学的国内外研究现状和理论基础进行了综述；深入研究问题解决的过程与方法的相关理论，并列举实例予以解释；依据问题提出和问题解决主体的不同，将问题解决教学分为四种类型，即教师提问—教师解决问题型、教师提问—学生解决问题型、学生提问—教师解决问题型和学生提问—学生解决问题型。四种类型的教学理论已应用于普通遗传学教学实践。本研究主要采用文献分析法、实践研究法、案例分析法、问卷调查法和数据统计分析法等研究方法。通过实践研究和统计分析得出如下结论：

1、问题解决教学可以提高学生的遗传学学习兴趣；

2、问题解决教学可以提高学生的自我效能感、问题意识、自主学习能力和交流合作能力；

3、本次问题解决教学实践短期内对遗传学学习成绩影响不明显。

【英文摘要】With the development of the society, new requirements of talent cultivation are putforward.They need to have good abilities for solving problems and nice

programming andorganizational ability;they should be good at communication and team work.However, thetraditional teaching is unable to meet those requirements.Research on the problem-solvingteaching becomes increasingly necessary.The thesis defines some relative conceptions on problem-solving teaching, summarizesthe rationale and the research status at home and abroad.Processes and methods of solvingproblem are discussed deeply, and many examples are enumerated to explain those theories.According to the difference in the partner of problem presenter and problem solver,problem-solving teaching is divided into four models, they are teacher present-teacher solvemodel, teacher present-student solve model, student present-teacher solve model and teacherpresent-student solve model.Four models were applied to teaching practice of generalgenetics.This research mainly uses literature analysis method, practice methodology, case analysismethod, questionnaire survey method, and statistical analysis method.The followingconclusions are drawn from the study:1.Problem-solving teaching could raise students’ interest levels on general geneticsstudy.2.Problem-solving teaching could raise students’ academic self-efficacy，questionawareness, independent learning capability and communication and cooperation ability.3.The problem-solving teaching practice failed to improve exam result.【关键词】普通遗传学 问题解决教学 教学类型 教学实践 【英文关键词】General genetics Problem-solving teaching teaching model teachingpractice 【目录】普通遗传学问题解决的教学设计及行动研究5-6背景9-10学的弊病99-10Abstract6

第一章 引言9-1

3摘要

第一节 研究

二、传统教

一、社会发展对人才的要求9

三、遗传学问题解决教学研究的必要性

一、研第二节 研究的内容、目的和意义10-1

1二、研究目的意义10-11究的内容10法1

1第三节 研究方第四节 创新之处11-13第二章 问题解决教学模

一、第二节 式概述13-29第一节 国内外研究现状分析13-16

二、国内研究现状15-16国外研究现状13-15问题解决教学相关概念的界定16-2116-19

一、关于“问题”

三、问题解决教第三节 问题解决教学

二、完形—顿悟

四、有意义学习理

二、关于“问题解决”19-20

20-21学(Problem-solving teaching)的理论基础21-29说23-2

4一、试误说21-2

3三、建构主义理论24-26论（奥苏贝尔和罗杰斯）26-29第三章 问题解决的过程和方

法29-37第一节 问题解决的过程

33-37

29-33第二节 问题解决的策略和方法析37-8

3第四章 问题解决教学设计及案例分

第二节 第一节 大学生学习特点分析37-38教材和其他可利用资源的分析38-39计及案例分析39-83研究83-9383

第三节 问题解决教学设

第五章 普通遗传学问题解决教学的实验

一、实验目的四、实

一、第一节 实验过程83-8

4二、实验假设8

3三、实验对象83验过程83-84第二节 前测、后测问卷的设计84-86兴趣量表的编制84-8

5二、自我效能感、问题意识、自主学

85-86

第三节 实验结

二、后测问卷分析第六章 实验结论和建

一、问题解决教学可

二、问题解决教学习能力和交流合作能力调查问卷的编制果86-9388-91议93-97

一、前测问卷分析86-88

三、后测成绩分析91-93第一节 实验结论93-9

493以提高学生学习遗传学这门学科的兴趣可以提高学生的自我效能感、自主学习能力、问题意识和交流合作能力9

3三、问题解决教学对提高学生的遗传学学习成绩没有明

第二节 实验的反思和建议94-9

5一、教

二、94显影响93-94学的设计要注意整体性，合理分配各个教学片段的时间94问题的提出是教学的前提，问题的解决过程是教学的核心

三、问题解决教学的应用中要注意与讲授式教学配合94-9

5四、四种类型的问题解决教学也需要相互配合9

5第三节 本

研究的局限性95-9799-107

参考文献97-99附录

附录 2 附录 1 生物学习兴趣水平量表99-101生物学习自我效能感、自主学习能力、问题意识和交流合作能力问卷101-103附录 3 遗传学学习兴趣水平量表103-10

5附录 4 遗传学学习自我效能感、自主学习能力、问题意识和交流合作能力问卷105-107科研成果108-109

致谢107-108

攻读学位期间取得的参考文献109-110

第二篇：2013春普通遗传学-作业题

东北农业大学网络教育学院

普通遗传学网上作业题(一)第一章

绪论

一、名词解释 1遗传学

2遗传

3变异

4遗传学研究

二、判断题

1遗传是相对的变异是绝对的。（）2 遗传和变异的表现与环境无关。（）3进化论可以离开遗传学独立发展。（）

三、填空题

1（）和（）生物界最普遍和最基本的两个特征。

2（）、（）和（）是生物进化和新品种选育的三大因素。3（）在1859年发表了《物种起源》。4（）是分子遗传学中最重要的研究方向。

四、简答题

1简述遗传学研究的任务？

五、论述题

1简述遗传学在科学和生产发展中的作用？

普通遗传学作业题(二)第二章

遗传的细胞学基础

一、名词解释

1细胞器

2细胞周期

3无融合生殖 4无性生殖

5有性生殖

6主缢痕

7孤雌生殖

8受精

9胚乳直感

10果实直感

11随体

12同源染色体

13性染色体

14联会

15单倍体

16多倍体 17拟核

18细胞骨架

19次缢痕

20核型分析 21无丝分裂

22无融合结子

23单性生殖

24单性结实 25生活周期

26世代交替

27低等生物无性世代

28低等生物有性世代

二、判断题

1细胞是生物体结构和生命活动的基本单位。（）2植物细胞的DNA都储存在细胞核和叶绿体内。（）3只有高等动物细胞才有中心体。（）4染色质和染色体实际是同一物质。（）5人体内不存在细胞无私分裂。（）6细胞周期分为G1期、S期和G2期。（）7常染色体主要是由常染色质所组成.（）

8无性繁殖的后代不象有性繁殖的后代那样发生分离。（）9我们通常在分裂后期研究染色体的形态。（）

10细胞周期中一个最重要的控制点就是决定细胞是否进入S期。（11高等动物都是雌雄异体的。（））

三、填空题

1细胞的分裂方式可分为（）和（）两种。

2减数分裂第一次分裂前期可分为（）（）（）（）（）五个时期。3高等植物的一个完整生活周期是从（）到下一代（），它包括（）和（）两个阶段。（）

4生物界的细胞分为（）细胞和（）细胞。（）5原核生物仅有的细胞器是（）。（）

6质膜对于（）、（）、（）、（）和（）等，都具有重要的作用。（）7（）是动植物细胞质中普遍存在的细胞器。（）8（）是绿色植物特有的细胞器。（）

9（）是在细胞质中数量最多，在整个细胞比重占有很大比例的细胞器。（）10（）是真核细胞质中广泛分布的膜相结构。（）

11（）是一场物质集聚的主要场所，对控制细胞发育和性状遗传起主导作用。（12根据着丝点的位置可以将染色体分为（）、（）、（）和（）。（13细胞周期主要包括细胞（）过程及两次分裂之间的（）。（）14植物的授粉方式分为（）和（）。（）15无融合生殖可以概分为两大类（）和（）。（）

四、简答题

1有丝分裂和减数分裂的主要区别？

2.植物的双受精是怎样进行的？用图表示。

3简述染色体次缢痕的作用。

4简述生物保持生长的的三个前提？

5有丝分裂的遗传学意义？

6减数分裂的遗传学意义？））

7简述植物细胞质里包括哪些主要细胞器？有什么特点？

五、计算题

1假定一个杂种细胞里含有3对染色体，其中A、B、C来自父本，a、b、c来自母本，通过减数分裂能形成几种配子？写出各种配子的染色体组成。

2.玉米细胞里有10对染色体，写出下列各组织的细胞中染色体数目。（1）叶（2）根（5）卵细胞（6）反足细胞（7）花粉管核（8）胚囊母细胞（9）花药壁

普通遗传学作业题(三)第三章

遗传物质的分子基础

一、名词解释 1半保留复制

2翻译

3遗传密码

4简并

5中心法则

6染色质

7常染色质

8异染色质 9复制子

10前导链

11后随链

12冈崎片段 13不均一核RNA 14小核RNA

15着丝粒

16全保留复制 17散布式复制

3）胚乳4）胚

（（18mRNA的功能

19多聚核糖体

二、判断题 5`UCA3`这个密码子的反密码子是3`AUG5`。（）2 DNA是所有生物的遗传物质。（）3所有生物的DNA复制都是双向的。（）

4DNA聚合酶Ⅲ才是活体细胞内真正控制DNA合成的酶（）5DNA复制是双向的都是从5’到3’方向进行。（）6DNA复制时两条链都是连续合成的。（）7DNA分子的双螺旋结构是左手螺旋的。（）

8染色体也和染色质一样有常染色质区和异染色质区。（）9tRNA是最小的RNA。（）

10一种蛋白质只能对应一个遗传密码（）11异染色质一般不编码蛋白质。（）

三、填空题

1核苷酸包括（）（）（）3部分。（）

2DNA含有的碱基是（）（）（）（）四种。（）3染色质的基本结构是（）（）和（）。（）4基因的表达第一步是（）第二步是（）。（）5三种RNA分子包括（）（）（）。（）

6（）是组成核糖体的主要成分，而核糖体则是合成蛋白质的中心。（）7异染色质可分为（）异染色质和（）异染色质。（）

8染色单体包括一条（）和位于线上的许多染色很深的颗粒状（）。（）9生物的染色体是（）和（）的复合物。（）

10证明DNA是主要遗传物质的三个经典实验是（）、（）和（）。（）

11假设某一段DNA分子链有一千对核苷酸，则该段就可以有（）种不同的排列组合方式。（12（）染色质可经转录表现出活跃的遗传功能。（）

13在细胞有丝分裂的中期，染色体的结构是由两条（）组成的。（）

14遗传物质不管其化学性质如何，必须具有（）、（）和（）等三种基本功能。（15（）的碱基顺序决定蛋白质的氨基酸顺序。（）16RNA转录可以分三步（）、（）和（）。

17RNA转录时上游指RNA分子的（）端，下游则指（）端。18中心法则所阐述的是基因的两个基本属性：（）和（）。（）））

四、简答题

1基因的三种基本功能？

2端体的功能？DNA的复制过程？

4真核生物DNA合成的特点？RNA合成与DNA合成的不同点？

6真核生物RNA转录的特点？mRNA的加工的步骤？

8瓦特森和克里克模型的主要特点？

9简述三种DNA聚合酶在决定DNA合成方面有一些共同的特性？

普通遗传学作业题(四)

第四章

孟德尔遗传

一、名词解释 1单位性状

2性状

3相对性状

4基因型

5杂种优势

6测交

7独立分配规律

8共显性

9镶嵌显性

10上位性

11多因一效

12一因多效

13纯合体

14复等位基因

15表现型

16杂合体

17概率

18致死基因

19互补基因

20积加作用 21重叠作用

22抑制基因

23基因互作

二、判断题

1表现型仅由基因型决定。（）

2孟德尔的分离规律可适用于多倍体。（）

3在多基因遗传中F1的3对杂合基因分别3对染色体上，减数分裂过程中，这3对染色体有8种可能的分离方式。（）

4据分配规律，杂种相对遗传因子发生分离，纯种遗传因子不分。（）5等位基因发生分离的时间是在杂种细胞进行减数分裂形成配子是发生的。（）6显隐性关系不会受到环境的影响。（）

三、填空题

1表现型是（）和（）作用下的具体表现。（）2基因互作可分为（）互作和（）互作。（）

四、简答题

1分离比例实现的条件？

2对于7对性状都在F2代出现3：1的分离比孟德尔作出了哪些假设？

五、论述题

1分离规律的应用？

2独立分配规律的应用？

六、计算题

1光颖，抗锈，无芒（ppRRAA）小麦和毛颖，感锈，有芒（PPrraa）小麦杂交，希望从F3 选出毛颖，抗锈，无芒（PPRRAA）的小麦10个株系，试问在F2群体中至少应选择表现型为 毛颖，抗锈,无芒（P_R_A_）的小麦多少株？

2小麦有稃基因H为显性，裸粒基因h为隐性。现以纯合的有稃品种（HH）与纯合的裸粒品种（hh）杂交，写出F1和F2的基因型和表现型？

普通遗传学作业题(五)第五章

一、连锁遗传和性连锁 名词解释

1交换值

2交换

3连锁遗传

4遗传图谱 5伴性遗传

6完全连锁

7干扰

8不完全连锁 9基因定位

10单交换

11性染色体

12交叉遗传 13限性遗传

14从性遗传

15着丝点作图

16畸变现象

二、判断题

1交换值都小于50%（）

2交换值越接近0%，连锁强度越大。（）3当符合系数为1时，表示发生完全的干扰。（）4性别分化受染色体的控制，也受环境的影响。（）

5除着丝点之外，非姐妹染色单体的的任何位点都可能发生交换。（）6交换值不受环境的影响。（）7符合系数常变动在0—1之间。（）

8常染色体的每对同源染色体往往是异型的。（）9雌雄和雄性的比例一般是1：1.（）

三、填空题

1由性染色体决定雌雄性别的方式主要有（）和（）两种类型。

2人类的性染色体属于（）型，有染色体（）对，其中常染色体有（）对，性染色体（）对。

3请写出下列杂交组合产生F1的遗传组成Srr×NRR→S（）×S（）, Srr×Nrr→（）×（）, Srr×SRr→（）×（）。

4一个成熟的花粉粒包括（）和（），这样的花粉粒在植物学上被称为雄配子体。5（）标致着各对同源染色体中的非姐妹染色单体的对应区段发生了交换。6（）和（）是基因定位所采用的主要方法。

7继孟德尔提出的两条遗传规律之后，（）成为了第三条遗传规律。

四、简答题

1简单概括一下性别决定问题？

2.什么是伴性遗传和限性遗传？它们的区别是什么？

3基因定位时，三点测验结果分析的要点是什么？

4试述遗传图谱和物理图谱的构建途径？

5简述重组型配子为什么少于50%？

6简述如何利用两点测验确定Aa、Bb和Cc对基因在染色体上的相对位置？

7如何利用三点测验来确定连锁的三个基因在染色体上的顺序？

五、计算题

1已知水稻的抗稻瘟病基因P与晚熟基因L都是显性，而且是连锁遗传的，交换值为2.4%。如果用抗病、晚熟材料作为一个亲本，与感病、早熟的另一亲本杂交，计划在F3选出抗病、早熟的5个纯合株系，这个杂交组合的F2群体至少要种植多少株？a和b是连锁基因，交换值为16%，位于另一染色体上的d和e也是连锁基因，交换值为8%。假定ABDE和abde都是纯合体，杂交后的F1又与纯隐性亲本测交，其后代的基因型及其比例如何？

3假定一个杂种细胞里含有3对染色体，其中A、B、C来自父本，a、b、c来自母本，通过减数分裂能形成几种配子？写出各种配子的染色体组成。

4在杂合体Aby//abY内，a和b之间的交换值为8%，b和y之间的交换值为12%，在符合系数为0.24时，配子的比例如何？

5已知玉米籽粒的有色（C）对无色（c）为显性，饱满（S）对凹陷（s）为显性以有色饱满的纯种与无色凹陷的纯种杂交获得F1，然后用双隐性纯合体与F1测交，结果如下：CcSs种子4032粒，Ccss种子149粒，ccSs种子152粒，ccss种子4035粒，计算交换值。

普通遗传学作业题

（六）第六章 染色体的变异

一、名词解释

1倒位

2易位 3顺接重复

4反接重复 5缺失

6缺失杂合体

7转移

8同源多倍体 9异源多倍体

10顶端缺失

11重复

12断片

13双着丝粒染色体

二、判断题

1只要是倒位杂合体减数分裂后期Ⅰ必将形成染色体桥。（）2易位可导致染色体融合。（）

3染色体的稳定是相对的，变异是绝对的。（）

4细胞内某基因出现的次数越多，表现型效应越显著。（）5易位与致癌基因的表达也有关系。（）

6同源三倍体的高度不育性在生产上无应用价值。（）

三、填空题

1染色体结构变异可分为（）、（）、（）和（2倒位可分为（）倒位和（）倒位。3重复对表现型的主要影响是（）。

四、简答题

1染色体组的最基本特征？）。

2染色体结构变异一般分为几类？各有何特点？

3简述如何鉴定缺失？

4倒位杂合体非姐妹染色单体之间在倒位圈发生交换可产生几种交换染色单体？

5简述利用缺失进行基因定位的关键？

五、论述题

1论述多倍体在农业生产上的应用？

2论述如何鉴定缺失？

3论述如何鉴定倒位？

4简述遗传学和育种学对单倍体研究有増无减的原因？

普通遗传学作业题

（七）第七章 细菌和病毒的遗传

一、名词解释

1温和性噬菌体

2转化

3接合 4转导

5质粒

6整合 7性导

8Hfr细胞

9特殊性转导

10无性繁殖系

11烈性噬菌体

转导体

13合转导

14宿主范围突变体

15普遍性转导

二、判断题

1一切生物均有细胞结构。（）

2病毒中没有合成蛋白质外壳所必须的核糖体。（）3病毒的遗传物质仅有RNA。（）4死的细胞病毒也可以浸染。（）

5合转导的频率越高，表明两个基因在染色体上的距离越近。（）6供体DNA分子可以是单链。（）

7供体DNA的分子数与细胞转化率直接相关。（）8供体DNA的分子数越多细胞转化率越高。（）9受体细胞不处于感受态时也能接受外源DNA。（）

三、填空题

1病毒的结构包括（）和（）。

2感染细菌的病毒叫做（），依其与宿主细胞的关系可分为（F因子是由（）组成的，可以看做（）以外的遗传物质。4转导与转化、性导的不同之处在于它以（）为媒介的。5从结构上讲（）是最简单的生物。6转导可分为（）转导和（）转导。

7影响供体DNA与受体细胞的互作的因素有（）、（）、（8细菌的遗传转化包括（）、（）和（）。

四、简答题

1简述细菌和病毒在遗传研究中的优越性？）和（）。）和（）两大类型。

2.F+、F-和Hfr菌株有何区别？

3比较转化，接合，转导，性导在细菌遗传物质传递上的异同？

4简述部分二倍体的重组与真核生物中完整的二倍体重组的不同？

5简述F’因子使细菌带有哪些突出特点？

五、论述题

1论述性导在大肠杆菌的遗传学研究的作用？

普通遗传学作业题

（八）第八章

一、基因的表达与调控 名词解释

1基因

2顺式排列

3反式排列

4顺反测验

5顺式调控

6反式调控

7基因调控

8负调控

9正调控

10乳糖操纵元模型

11转录因子

12转录强化子 13激活子

14自动调控

15甲基化

16信号肽

二、判断题 负调控与正调控并非相互排斥的两种机制。（）2 在降解代谢途径中，既有正调控又有负调控。（）3 阻遏蛋白只有两个结合位点。（）4 染色体结构的变化可以控制基因表达。（）5 甲基化可以降低转录效率。（）6原核生物基因也有TATA盒结构。（）7强化子只能位于基因的上游。（）

8哺乳动物产生的每一种抗体都具有与抗原结合的能力。（）9所以真核生物的基因都只有一个启动子。（）10我们说的基因不表达通常指基因完全不表达。（）

11乳糖操纵元中的“开关”系统也适合合成代谢途径中的基因调控。（）12真核生物翻译多肽的过程是在细胞核中完成的。（）

三、填空题

1原核生物基因表达的调控主要发生在（）。2在真核生物中，（）是细胞分化和功能的核心。3 DNA变化包括基因的（）、（）和（）。4 真核生物基因启动子包括所有（）以及（）。强化子与启动子不同，（）是转录起始和达到基础水平所必须的，而（到最高水平。

6正激活子包括（）和（）。

7大部分遗传性状都是直接或间接通过（）表现出来的。8基因对于遗传性状的表达的作用可分为（）与（）。9（）作用是色氨酸操纵元调控中的关键。

10内含子蛋白质的一个重要特点是具有（）的能力。

四、简答题

1经典遗传学和分子遗传学关于基因概念的不同？

2随着基因结构和功能的深入研究，可将基因分为哪几种类型？）则可以使转录达3按照现代遗传学的概念，基因根据重组、突变、功能可分为哪几个单位？

4简述原核生物转录水平的调控的特点？

五、论述题

1论述真核生物基因调控的特点？

普通遗传学作业题

（九）第九章

一、基因工程和基因组学 名词解释

1基因工程

回文对称序列

3柯斯质粒

4穿梭载体 5基因库

6核基因库

cDNA库

8植物基因转化 9基因组学

10后基因组学DNA微列阵

12蛋白质组学 13生物信息学

14Western杂交

15植物基因转化

16基因枪植物转化 17基因治疗

18DNA芯片

19辐射杂交系

二、判断题 经过限制性酶切的基因皆产生粘性末端。（）2荧光原位杂交是遗传图谱构建的方法。（）

3当供体材料总DNA等量时，DNA杂交带的信号强弱与该标记位于得染色体剂量成正比。（）

三、填空题

1广义遗传工程包括（）、（）、（）等。

2Ti质粒具有（）、（）、（）、（）和（）五个功能区域。一般说来，一个基因就是编码一条多肽链的一个DNA片段，包括（4根据克隆的核酸序列、来源，基因库可分为（）、（）、（5常用的染色体定位方法有（）（）（）。6PCR反应包括（）、（）和（）三个步骤。

四、简答题

1基因工程技术主要包括的内容？

2载体应具备的条件？

3简述基因图谱的应用？

4简述Southern杂交的步骤？

5简述Nouthern杂交的步骤？

6简述基因组计划可分为几部分？

五、论述题

1论述如何构建植物图谱？

2论述物理图谱的构建途径？、（）和（）、（）等。）。）

普通遗传学作业题(十)第十章 基因突变

一、名词解释 1基因突变 2突变体

3位点

4座位

5转座遗传因子

6插入因子

7转座子

8Mu噬菌体

9大突变

10微突变

11自交不亲和性

12中性突变

二、判断题

1基因突变是随机的。（）

2突变可以发生在生物体发育的任何时期。（）3基因突变通常是对立发生的。（）4突变就是基因内不同座位的改变。（）5高等生物的突变率比低等生物的突变率高，（）6只有体细胞能够发生突变。（）

7镶嵌范围的大小取决于突变发生时期的早晚。（）8具有突变的方向是不定的，可以多方向发生。（）9正突变与反突变发生的频率是一样的。（）

三、填空题

1（）发生的突变可以通过受精过程直接传给后代，而（2突变的发式主要有（）和（）。3突变可分为（）突变和（）突变。

4DNA的修复主要有（）、（）、（）和（5在多数情况下正突变率总是（）反突变率

四、简答题

1基因突变的一般特征是什么？）不能。）四种形式。DNA的防护机制？

3简述诱变剂的诱变机理？

4基因突变的平行性说明什么问题，有何实践意义？

5简述重组修复的步骤？

五、论述题

1转座因子的应用？

普通遗传学作业题(十一)第十一章

细胞质遗传

一、名词解释

1核遗传

2细胞质遗传

3母性影响

4共生体 5雄性不育性 6附加体 7质核不育型

二、判断题

1雄性不育的植株不能结实。（）2雄性不育是由核基因决定的。（）

三、填空题

1可遗传的雄性不育性可分为（）和（）等多种类型。2（）是雄性不育基因的载体。

四、简答题

1细胞质遗传和母性影响的区别？

2简述雄性不育性的主要特征？

3质核不育型的特点？

4什么叫细胞质遗传？它有哪些特点？

普通遗传学作业题(十二)第十二章 遗传与发育

一、名词解释

1细胞全能性

2植物的诱导抗性

二、判断题

1细胞的仅由细胞核起作用。（）2生物个体的发育与环境无关。（）

3高等生物受精卵的初期分裂就是不等的。（）

三、填空题

1（）和（）是细胞生存必不可少的两部分。

四、简答题

1如何理解细胞核和细胞质在个体发育中的相互依存？

2个体发育的特点？

五、论述题

1简述利用植物细胞的全能性在作物育种上获得的成就？

普通遗传学作业题(十三)第十三章

数量遗传

一、名词解释

1广义遗传率 2狭义遗传率 3质量性状 4数量性状 5加性效应 6显性效应 7杂交 8异交

9近交 10杂种优势 11平均优势 12超亲优势 13杂种劣势 14主效基因 15微效基因

二、判断题

1远亲交配能表现杂种优势。（）

2多基因控制的一般表现质量性状的特征。（）

三、填空题

1生物群体的变异包括（）和（）。2个体的表现型值是（）和（）的总和。3数量性状QTL定位的基础需要有（）。4在数量性状遗传中，基因型方差可分解为3个部分（）、（）、（）。

四、简答题

1.何谓质量性状和数量性状，它们的区别在哪里?

2简述多基因学说？

3区间作图法的优点与问题？

4简述杂种优势的三种类型？

5杂种优势表现的特点？

普通遗传学作业题

（十四）第十四章

群体遗传与进化

一、名词解释

1群体遗传学

2孟德尔群体

3基因型频率

4等位基因频率

二、判断题

1当环境条件或遗传结构改变时，等位基因频率也会改变。（）

三、简答题

1简述哈迪-魏伯格定律的要点？

第三篇：普通遗传学 第13章 教案

第13章 基因突变 教案

基因突变在动物、植物、细菌和病毒中广泛存在，人类可利用基因突变进行育种。

基因突变既可自然发生也可人工诱变，而且诱发突变成位育种材料的一种重要手段。

一、目的和意义

了解基因突变的种类，原因以及突变与性状表现的关系。如何诱发基因突变。

二、重点内容：

1、自发突变的原因（辐射。温度的极端变化。过高或过低。化学物质主要体内或细胞内某些生理、生化过程所产生的物质的作用。）

2、基因突变的概念

基因突变的概念及其类别

最初突变的概念:DeVries1901～1903.研究月见草的变异,指突然发生的变异（实际上是染色体畸变）,现在遗传学上指的突变一般指基因突变。

基因突变:由于基因内部某一位点的结构发生改变（化学变化）,使其由原来的存在状态而变为另一种新的存在状态,即变为它的等位基因。又称为点突变（pointmutation）。带有突变基因的细胞或个体叫做突变体（mutant）。基因突变是可以遗传的。

3、类别:按其发生的原因可分为

(1)自发突变（spontaneousmutation）。丰自然情况下发生的突变。

(2)诱发突变（inducedmutation）。人们有意识地利用物理、化学诱变因素引起的突变。（射线、温度）。这两类突变在表现形式上没有原则上的区别。

按其表形特征可分为

(1)形态突变型（mirphologicalmutation）。泛指外形改变的突变型。因为这类突变可在外观上看到,所以又称可见突变（visiblem.）。

(2)致死突变型（lethalmulations）:能引起个体死亡或生活力明显下降的突变型。分显隐性、全致死（>90%）、半致死（50～90%）、低活性（50～10%）。隐性致死较为常见。

(3)条件致死突变型:在一定条件下表现致死而在另外条件下能成活的突变型（conditionallethalmutation）。T4的温度敏感型在25℃时能成活,42℃致死。(4)生化突变型（biochemicalmutation）。没有形态效应但导致某种特定生化功能改变的突变型。表现在补充培养基上能生长。

事实上,以上类型相互之间是有交叉的。几乎所有突变都是生化突变。

4、基因突变的一般特征

A、自然条件下突变的频率低。一般地，细菌和噬菌体等为10～10，高等生物10～10，然而，微生物繁殖周期短，实际更易于获得突变体。突变还受生物体内在的生理生化状态，以及外界环境条件（包括营养、温度、化学物质和自然界的辐射等）的影响，其中以生物的年龄和温度的影响比较明显。比如在诱变条件下，一般在0-25℃的范围内，每增加10℃突变率将提高2倍以上。当温度降到0℃时也有所增加，在老龄种子的细胞内，常产生某种具有诱变作用的代谢产物——自发诱变剂，从而提高了突变频率。B、突变的多方向性

突变的多方向性也是相对的，是在一定范围内的多方向性。C、突变的重演性：

同种生物中同一基因突变可在不同个体间重复地出现。也的也称为平行性。-

4-10

5-8D、突变的可逆性：

一个叫正向突变，一个叫回复突变。E、突变的平行性：

亲源关系相近的物种因遗传基础比较近似，往往发生相似基因突变。F、突变的有利性与有害性：

多数突变改变了原来的功能，功能的改变对生物往往有害。当然少数个别的是有利的（如大肠杆菌的抗性突变等），还有少数既无害又无利——中性突变。突变发生的时期和部位：

G突变可发生在任何时期，任意部位。

发生在体细胞——当代表现；发生在生殖细胞——传给后代。

控制细胞分裂的基因发生了突变——癌症，造成某些功能的丧失，后期死亡的速度很快，为当代表现，为体细胞的变化。

5、基因突变的诱导：物理因素（电离辐射、非电离辐射）

化学因素（碱基类、烷化剂、抗生素类）

6、基因突变的鉴定（1）利用分离规律 1.显性突变: 2.隐性突变:

由于处于杂合状态而不表现,在进行杂合体自交或偶然自交的情况下才能表（第二代有纯合的隐性突变型）。

（2）微生物营养缺陷型的测定筛选方法

7、基因突变的分子基础（1）突变的两种方式

a碱基替代(basesubstitution)：某一位点的一个碱基对被其他碱基对取代。碱基替换包括两种类型。

转换（transition）：是同型碱基之间的替换,即一种嘌呤被另一种嘌呤替换。或一种嘧啶被另一种嘧啶替换。

颠换（transversion）：嘌呤和嘧啶之间的替换。即嘌呤为嘧啶代替,嘧啶为嘌呤代替。

b移码突变：DNA分子中增加或减少一个或几个碱基对,引起密码编组的移动（frameshiftmutation）。（2）、突变产生的机理 a．互变异构化：

一个质子的位置变化而改变了碱基氢键的特性。b．碱基类似物（baseanalogues）：

是在化学结构上与DNA的碱基很相似的物质,在DNA复制时,“冒充”碱基掺入到DNA链中去。c．亚硝酸（HNO2）的作用： 具有氧化脱氨的作用。

d．烷化剂的作用：

具有一个或多个活性烷基的化合物（alkylatingagents）

作用：使DNA中的碱基发生烷化作用。如添加甲基或乙基,产生配对误差。如甲基磺酸乙酯（EMS）e．吖啶类化合物：

原黄素,吖啶橙等。为三环扁平的分子,大小与碱基对的大小差不多,能与DNA结合,嵌入DNA的碱基对之间,使相邻的两个碱基对的距离拉长,使DNA双链歪斜,导致DNA交换时出现参差,结果导致不等交换,产生移码突变。

吖啶类诱发的突变的一个重要特征是：吖啶类化合物所诱发的突变能用吖啶类来回复,但不能用碱基替换来回复。假使在一个碱基插入点的附近,以后又丢失了同样数目的碱基或者相反,突变效应往往可以被抑制。但这不是真正的回复突变,而是抑制突变。如果两个位点中还包括终止密码,就不能回复。

三、难点内容：

1、性状的变异与原因

2、基因突变的鉴定

3、基因突变的分子基础

四、课程时间安排 第一节基因突变的时期

1、基因突变的时期

2、一般特征 第二节基因突变与性状表现

1、显性突变与隐性突变的表现

2、大突变和微突变的表现

第三节基因突变的鉴定

1、植物基因突变的鉴定

2、生化突变的鉴定 第四节基因突变的分子基础及诱发

1、突变的分子机制

2、突变的修复

3、物理因素和化学因素

五、参考文献

华北农业大学等，1976，植物遗传育种学，北京，科

学出版社

杨业华，2000，普通遗传学，北京，高等教育出版社 贺竹梅，2002，现代遗传学教程，广州，中山大学出

版社

刘祖洞，1991，遗传学，北京，高等教育出版社 浙江农业大学主编，遗传学，1989，北京，农业出版社 蔡旭主编，植物遗传育种学，1988，北京，农业出版社

第四篇：普通遗传学 第8、9章 教案

第八、九章 染色体变异 教案

染色体变异分为结构变异和数目变异。结构变异包括缺失、重复、倒位和易位，均由染色体断裂引起；数目变异包括整倍体变异和非整倍体变异。常见的整倍体变异有单倍体、同源多倍体和异源多倍体，非整倍体变异有单体和三体。

一、目的和意义

了解染色体结构变异和数目的主要方式及由此引起的结果。

二、重点内容：

1、染色体结构变异的类型

（1）缺失—一条正常的染色体丢失常有基因的片段

A 方式：中间缺失、顶端缺失 B类型：缺失杂合体、缺失纯合体

C缺失的遗传效应：不利性。不利程度取决于缺失片断上基因的数量和重要性。缺失纯合体不利性远大于杂合体。假显性（缺失杂合体）。植物缺失的染色体多通过卵细胞来传递。因为带有缺失染色体的雄配子常是败育的，即使不败育竞争力也差。而卵细胞在母体内，耐受性比雄配子强。

D鉴定：细胞中有无断片、微核、及同源染色体配对情况/缺失环。缺失杂合体中间缺失较长时同源染色体配对时出现。配对的同源染色体末端长短不一（端部缺失区段较长）有时出现“断裂—融合—桥”循环

（2）重复——染色体重复自己染色体的某段基因

A类型：重复杂合体、重复纯合体

B遗传效应：不利性。程度比缺失轻，正常的二倍体中的两套基因处于平衡状态。重复影响到基因平衡。（3）倒位——一条染色体的发生两处断裂，断裂间的染

色体片段倒位180°之后的结合的现象。

A类型：臂间倒位、臂内倒位 B原因：减数分裂、理化因素诱导

C遗传效应：改变了连锁基因之间的重组值，变大或变小。倒位区段内的基因表现出很强的连锁关系。减数分裂时可见到桥和断片。

（4）易位——某一染色体的断裂片段转移到另一非同源染色体上

A类型：单向易位(少见)、相互（常见）

B遗传效应：改变了原来的连锁关系；易位杂合体往往出现半不育。同源染色体分开时，到达两极时形成四种配子，有一半不育。易位杂合体出现假连锁现象。由于相邻式分离配子，交替式分离配子可育，因而可育配子只能是易位染色体和非易位染色体进入不同配子中，结果使非同源染色体上基因的自由组合受到严重的抑制，出现假连锁，在雄果蝇中表现尤明显。在邻近易位接合的一些基因之间的重组值有所降低。

C鉴定：相互易位为杂合体，易位较长时，在减数分裂时，形成“十”字形结构。

2、常见的染色体数目变异的类型中相关的基本概念 染色体组（genome）：在一个染色体组内的各个染色体在形态、结构和功能方面互不相同，但却是一个和谐的整体，对于细胞或个体的发育来说，是缺一不可的。

一倍体（monoploid）：只含有一个染色体组的个体或细胞，如二倍体生物的配子，如玉米x=10，蜜蜂的雄蜂x=16 二倍体（diploid）：含有二个染色体组的个体或细胞。一般生物。

三倍体（triploid）：具有三个染色体组的细胞或个体。如三倍体西瓜。

四倍体（tetraploid）：具有四个染色体组的细胞或个体。如4倍体蕃茄x=124x=48 多倍体（polyploid）：细胞或个体中的染色体组数多于二个。

整倍体（euploid）：一倍体、二倍体、多倍体，这类染

色体的变化是以染色体组为单位的增减，所以称为倍数性变异，而把体细胞

内含有完整的染色体组的类型称为整倍体（euploid）。

非整倍体（uneuploid）：如果在二倍体的基础上，增加

或减少个别染色体，则属于非整倍性（uneuploidy）变异，这种变异的细胞或个体叫非整倍体（uneuploid）。

同源多倍体：加倍的染色体组来源相同，由二倍体本身的染色体加倍而成。现已成功诱变出水稻、大麦、黑麦、桑、茶、葡萄、西瓜、板栗等多种四倍体植物。

异源多倍体：加倍的染色体组来源于不同的物种。被子植

物中约有30～35%是异源多倍体物种。小麦、燕麦、棉花、烟草、苹果、梨、樱桃以及菊、大丽菊、水仙、郁金香等。

三、难点内容：

1、染色体结构变异的发生现象的解释

2、染色体结构变异的遗传效应

3、同源多倍体和异源多倍体的区别

四、课程时间安排： 第一节染色体结构变异

1、缺失

2、重复3倒位、4、易位 第二节染色体数目变异

1、倍数性的变异

2、非倍数性的变异

五、参考文献

浙江农业大学主编，遗传学，1989，北京，农业出版社 李竞雄，宋同明，植物细胞遗传学，1993，北京，科学出版社

GriffithaA.J.F.etal,1999,ModernGenetiAnalysis.NewYork 王亚馥，戴灼华，1999，遗传学，北京，高等教育出版社

第五篇：遗传学双语教学习题

山东农业大学

遗传学双语教学章节习题

Problems and Questions

Contents

Chapter 1 An introduction to Genetics Chapter 2 Cytology for Genetics —— Mitosis and Meiosis Chapter 3 Molecular basis for Genetics Chapter 4 Mendelian Genetics Chapter 5 Linkage and Sex linkage Chapter 6 Chromosome Mutations: Chromosomal Changes, Monosomy, Trisomy, Polyploidy, Structural Changes Chapter 7 Genetics in Bacteria and Bacteriophages Chapter 8 Gene expression and Control Chapter 9 Gene Engineering and Genomics and Proteomics Chapter 10 Gene Mutation Chapter 11 Extranuclear Inheritance and Maternal Effect Chapter 12 Genetics and Development Chapter 13 Quantities Genetics Chapter 14 Population genetics and Evolution

Chapter 1 An introduction to Genetics

1.Distinguish between haploid and diploid in a manner that makes it clear that you know what each is and how the two differ.2.Define the term “gene”.Include in your answer a brief description of the function of a gene.3.Distinguish between transcription and translation in a manner that makes it clear that you know what each is and how the two differ.4.What is a gamete and why is it considered important in the study of genetics? 5.What is a zygote and why is it considered important in the study of genetics?

6.Distinguish between gene and genome in a manner that makes it clear that you know what each is and how the two differ.7.In molecular terms, how would you define mutation?

8.How is the information that specifies the amino acid sequence of a protein passed from one generation to the next?

9.Distinguish between genotype and phenotype in a manner that makes it clear you know what each is and how the two differ.10.What genetic mechanisms make it possible for individuals with different genotypes to exhibit the same phenotype.11.What is a chromosome and how does it differ from a gene?

12.Can a gamete be heterozygous? Explain the reasoning behind your answer.13.A typical organism has far more genes than chromosomes.Will all of the genes exhibit independent assortment? Explain the reasoning behind your answer.Chapter 2 Cellular basis of Genetics

1.Distinguish between mitosis and meiosis in a manner that makes it clear that you know what each is and how they differ.2 2.Compare the length of the meiotic prophase in human males and females.Which more closely resembles mitotic prophase.How do both differ from mitotic prophase?(See page 332 of the textbook if you have difficulty with this question).3.Briefly summarize the major events in a haploid-diploid life cycle.Identify a species with a predominantly haploid life cycle and a species with a predominantly diploid life cycle.4.What abbreviations are used to designate the four parts of the mitotic cell cycle and what does each stand for?

5.Distinguish between karyokinesis and cytokinesis in a manner that makes it clear that you know what each is and how they differ.6.Name and briefly describe the four stages that mitosis is commonly divided into.(Caution, this is not a repeat of question 4).7.Describe two distinctly different processes that occur during meiosis to bring about mixing of the two parental genotypes during formation of gametes.Identify the stage of meiosis at which each occurs as precisely as you can, and briefly describe the mechanisms that are involved.8.Identify the five stages of meiotic prophase and briefly describe each, including important genetic events that are occurring during that phase.9.What role does mitosis play in a sexual life cycle?(Why do sexually reproducing organisms need mitosis at all?)

10.At what stage of meiosis does crossing over(genetic recombination)occur?(see page 331 of textbook if you are uncertain).11.What are chiasmata and what is their genetic significance?

12.At what stage of meiosis is independent assortment of unlinked genes achieved? What is the mechanism that is involved?

13.At what stage during meiosis do the centromeres of the individual sister chromatids separate? 14.At what stage of meiosis is the chromosome number reduced to haploid(bivalents with sister chromatids still paired count as single chromosomes).15.At what stage of meiosis is the DNA content per gamete reduced to haploid?

16.In terms of genetic uniformity of the ultimate products of each process, how do mitosis and meiosis differ?

17.What is a lampbrush chromosome and under what circumstances is it observed?

Briefly define each of the folowing and explain its genetic significance or its significance to the study of genetics.a.Homologous chromosomes.b.Tetrad.c.Synaptonemal complex d.Biparental inheritance.e.Gametophyte.19.What are the consequences of nondisjunction during one or the other of the meiotic divisions? 20.A human female has 23 pairs of chromosomes.Assuming that the members of each pair differ from each other, how many different different gametes does she have the potential ability to generate, based on independent assortment alone?

21.Meiosis in a female generates one ovum and 3 polar bodies, whereas in a male meiosis generates 4 spermatozoa.Does this result in four times as much genetic diversity in male gametes as in female gametes? Explain the reasoning behind your answer.22.The part of the mitotic cell cycle that was originally viewed simply as “interphase” is now viewed quite differently.a.How was interphase defined and what criteria were used to define it?

b.Identify the three parts that interphase is now divided into and explain the original significance of each of the three parts.c.How has modern research changed our view of the first and third segments of “interphase”? 23.Meiosis generates genetic diversity, whereas mitosis maintains genetic constancy.Explain how this is advantageous to the organism.24.There is evidence that transcription continues in oogenesis, even after meiotic prophase has begun.a.What is the evidence for transcription during meiotic prophase? b.Speculate on what biological purpose such transcription serves.Chapter 2 Cellular basis of Genetics(Molecular basis for Genetics)1.Briefly summarize the flow of information from a gene to a final gene product, including the form that the information takes at each step along the way and the names of the major processes that are involved in achieving the flow of information.2.Distinguish between prokaryotic and eukaryotic in a manner that makes it clear that you know what each is and how they differ.4 3.Summarize two different lines of evidence that have demonstrated that DNA is the primary carrier of genetic information.4.Identify the four nitrogenous bases that are used for the coding of genetic information in DNA.How are they related to the bases used for coding genetic informaiton in RNA?

5.What are the chemical differences between DNA and RNA? You should be to identify two that are always true and a third that is usually true.6.What is a phosphodiester link and how does it give polarity to nucleic acids? 7.Identify the base pairs in DNA.Which pairs are more stable and why? 8.What is meant by the term “antiparallel” as it applies to double helical DNA?

9.Distinguish between sense and antisense strands in a manner that makes it clear you know what each is and how they differ.10.What factors determine how rapidly DNA renatures after being denatured?

11.Distinguish between transcription and translation in a manner that makes it clear that you know what each is and how they differ.12.Explain how electrophoresis can be used to separate nucleic acid molecules by size.What role does the gel play in the process?

13.The nucleotide sequence of the sense strand of a double helical DNA molecule is ATGCGTAACTAACCG.a.What nucleotide is at the 5'-end? b.What nucleotide is at the 3'-end?

c.How would you distinguish the 5'-end from the 3'-end if the bases were the same at both ends? d.What is the nucleotide sequence of the complementary strand?(You always start at the 5'-end when describing a nucleotide sequence).e.What will be the nucleotide sequence of the mRNA that is transcribed from this DNA? 14.Ribose and deoxyribose are both 5-carbon sugars.a.What is the difference between ribose and deoxyribose?

b.What is attached to carbon #1 of these sugars when they are in nucleic acids? c.What is attached to carbon #3 of these sugars when they are in nucleic acids? d.What is attached to carbon #5 of these sugars when they are in nucleic acids?

e.Ribothymidine is an unusual nucleoside that can be recovered from certain types of transfer RNA(transfer RNAs contain a variety of modified bases).What is unusual about finding ribothymidine in a nucleic acid? 15.The genome of E.coli is a closed circle of double helical DNA that contains 4,639,221 base pairs(based on sequence analysis-see page 208 of the textbook).Based on your knowledge of the DNA double helix, answer the following.a.What is the thickness on one base pair in double helical DNA?

b.How many complete turns of the double helix are contained in the E.coli genome? c.What is the circumference of the circular genome when it is laid out as a perfect circle? d.What is the diameter of the genome when it is laid out as a perfect circle.e.An E.coli cell is relatively short cylinder only about 2 micrometers in diameter.How can that much DNA fit into it.(Hint, look at figures 7.6 and 7.7).16.What does each of the following abbreviations stand for? a.ATP b.dGTP c.UMP d.RNA e.cAMP f.mRNA g.TDP

17.Explain the importance of the flat planar structure of DNA base pairs to the double helical structure of DNA?

18.Explain why AC and GT base pairs do not normally form.(You will have to go to Example 2.3 on page 31 of the textbook to answer this one--I expect you to read the textbook in addition to the lecture notes!)

19.Distinguish between nucleoside and nucleotide in a manner that makes it clear that you know what each is and how they differ.20.One very promising technique for inhibiting unwanted gene expression is the use of antisense RNA, which has a sequence identical to that of the antisense strand of DNA(except for replacement of T with U).Speculate on how antisense RNA might inhibit functional gene expression, based on what has been presented in the course thus far.(We will examine what actually happens later in the semester).Chapter 3 Mendelian Genetics

1.Describe the genotypic and phenotypic ratios for each of the following(assume the parental generations are true breeding when not stated otherwise): a.The F2 of monohybrid cross with full dominance b.The F2 of monohybrid cross with partial dominance c.The F2 of a monohybrid cross with codominance.d.The F2 of a dihybrid cross with full dominance at each genetic locus and no interactions between alleles at the two loci.e.The F2 of a dihybrid cross with partial dominance at both loci and no interactions between alleles at the two loci.f.The F2 of a dihybrid cross with codominance at both loci and no interactions between alleles at the two loci.2.How would you distinguish between partial dominance and codominance(Be careful, you can get yourself thoroughly confused if you try to carry this too far).3.How would you distinguish between partial dominance and full dominance(again be careful).4.Describe a situation in which full dominance by certain criteria becomes partial dominance when examined by other criteria.5.Briefly describe three different genetic mechanisms that can cause the phenotype of a heterozygote A1A2 to be different from that of either of the corresponding homozygotes.A1 and A2 are alleles at the same genetic locus, but you may designate any type of relationship between the two of them that you wish, as long as it corresponds to something that happens in real life.Cite an example of each of the mechanisms that you propose.(Yes, there really are at least three possibilities!)

6.When two indivduals exhibiting dominant traits associated with homozygous lethality(for example, Manx cats)are crossed, altered Mendelian ratios are observed among the progeny.a.What phenotypic ratio is observed among the immediate progeny of such a cross? b.What mechanism is responsible for the altered phenotypic ratio?

c.Explain why it is not possible to obtain a true-breeding strain of Manx cats.d.What is the rationale for calling such a trait dominant when it is impossible to obtain a true-breeding line in order to do a classical dominant x recessive cross?

e.Explain the potential relationship between dominant lethal alleles and haploinsufficiency.7.Explain how a short deletion can generate phenotypic behavior that appears to be dominant lethal, but actually involves two separate genes.8.Why are dominant lethal alleles rarely observed in nature, as opposed to laboratory or domesticated strains?

9.There are three different alleles at the genetic locus responsible for human ABO blood types.a.What mechanism prevents all three alleles from being expressed in a single individual? b.Would it make any difference if all three alleles were codominant? Explain your answer.c.A woman with blood type A is married to a man with blood type B.Their first child is type O.Describe two distinctly different mechanisms that might allow this to happen.d.If only the ABO locus is involved, what blood types would be expected and in what ratio if the couple in part c have enough additional children to include all possible types.Ignore statistical problems due to small sample size.e.How does the ABO*O allele differ from the ABO*A and ABO*B alleles?

10.How many different genotypes are possible at a locus that has 5 alternative alleles? 11.How many of the genotypes in problem 10 can be observed in any one individual?

12.A man is blood type A and his wife is blood type B.Their first child is a girl with blood type O.a.What are the genotypes of the parents?

b.What was the probability of that child's birth among all of the other possible children that the couple could have had?(Be sure to consider both blood type and gender.)c.What is the probability that the next two children will both be blood type A? d.What is the probability that those two children will be one boy and one girl?

e.The couple ultimately has six children.Knowing that the first is a girl with blood type O, what is the probability that they will have two more girls with blood type O?(Be careful--this question is designed to confuse you!)

f.What is the probability that the fourth child will be a boy with blood type AB and the fifth a girl with blood type B?

13.Explain how a single point mutation can have multiple different phenotypic effects.What name is applied to this phenomenon?

14.Briefly explain how each of the following behaves in genetic analysis, including the mechanisms that are involved when they are known.a.Gain of-function-mutation.b.Leaky mutation

c.Dominant loss-of-function mutation d.Haploinsufficiency e.Codominance

15.In Drosophila genetics, e designates ebony body and L designates lobed eyes.What phenotype would you expect for each of the following.a.e/e+

b.e/e

c.L/+

d.e/e+ L/L+

e.L+/L+

16.Explain why an individual who is FUT1*O/*O and ABO*A/*B fails to exhibit the AB blood type.17.What syndrome would you expect an individual who has the genotype HBB*E7V/*E7V to exhibit.(HBB refers to the hemoblobin beta globin subunit.If you need more information, see textbook pages 159-161 and remember that the N-terminal methionine is removed soon after translation occurs.18.What circumstances would lead to each of the following phenotypic distributions in the F2 generation?.a.9:3:3:1 b.6:3:3:2:1:1 c.4:2:2:2:2:1:1:1:1 d.2:1 e.3:1 19.Briefly define each of the following, including a description of how you would verify that it was occurring:.a.Dominant inhibition of gene expression b.Codominance c.Complementary gene action.d.Duplicate gene action.e.Recessive epistasis.20.White leghorn chickens have normal pigment genes, but are white because of a dominant color inhibiting gene(I).White Plymouth rock chickens are white because they are homozygous for a recessive loss of pigmentation gene(c)that behaves much like the coat color gene(C/c)in mice.The genes are unlinked and neither is sex-linked.A true-breeding white leghorn(II CC)is crossed with a true-breeding white Plymouth Rock chicken(ii cc).a.What is the genotype of the F1 progeny? b.What is the phenotype of the F1 progeny?

c.Draw a Punnett square for the F2 whose individual squares are large enough to enter both the genotype and the phenotype of all possible combinations.Insert the genotypes and the phenotypes into the squares.d.What is the phenotypic ratio of the F2 progeny of the original cross?

21.What circumstances would lead to each of the following phenotypic distributions in the F2 generation? a.9:3:3:1 b.12:3:1 c.12:4 d.9:7 e.15:1 f.9:6:1 g.9:4:3

22.Explain how two parents who are both afflicted with a particular non-lethal phenotype, such as deafness, can have children who are not afflicted.You may make any assumptions you wish about the mode(s)of inheritance of the phenotype.You should be able to come up with two totally different answers for this question.23.Distinguish between penetrance and expressivity in a manner that demonstrates that you know what both are and how they differ.24.What mechanism is responsible for black ears and a white body coat on a Himalayan rabbit?

25.A true-breeding eyeless fly(ey/ey)is mated with a true-breeding brown eyed fly(bw/bw).Assume that both mutations are recessive and are located on different autosomes and that both have 100% penetrance(which is not always true for eyeless in real life).a.What will be the phenotype of the F1 progeny? b.What will be the phenotypic distribution when the F1 progeny are test corssed? c.What will be the phenotypic distribution of the F2 progeny of the original cross? d.What fraction of the brown-eyed F2 flies are heterozygous for the eyeless allele? e.What fraction of the wild-type F2 flies are heterozygous for the eyeless allele?

Chapter 4 Linkage and Sex linkage Lecture 30: Linkage, gene order, chromosomal maps

1.For all parts of this question, assume that both parts of the double crossover involve the same two strands of the tetrad.a.What is meant by the term double crossover?

b.How many linked genes must be analyzed to observe a double cross-over? c.What is the effect of a double crossover on the linkage pattern of the genes that are used to observe it?

d.How do you compensate for the effects of double crossovers when calculating map distance between the two outside markers? e.Explain why it is not possible to demonstrate double crossover when using only two markers.2.Describe the steps that must be taken to identify the middle gene in a three point cross.3.A female Drosophila heterozygous for linked autosomal genes, a, b, and c is crossed with a male that is homozygous recessive for all three genes.The female progeny exhibit the following phenotypes.+++, 340;abc, 350;++c, 45, ab+, 55;+b+, 95;a+c, 105;a++, 4;+bc, 6.Total flies counted = 1000.10 a.Which is the middle gene?

b.What is the corrected map distance between the two outside genes?

c.Why would a two point cross between the two outside genes not yield the same value as the corrected map distance?

d.What is the interference value for the double crossover?

e.Would it have made a difference in the original cross if the genes had been sex linked and the male was hemizygous for all three recessive alleles.Explain your answer.f.Could you use a wild type male in question e? Explain your answer.g.How would the observed results have differed if the male parent had been heterozygous and the female parent homozygous recessive?

4.You are working with three autosomal genes in Drosophila whose possible linkage is not known.A three point cross of a female heterozygous for all three genes with a male that is homozygous recessive for all three yields roughly equal numbers of all of the possible phenotypes.a.What alternative interpretations of the data are possible?

b.What additional experiments would be needed to distinguish among the possibilities? c.Would your answer to part b be the same if you were studying mutations in mice?

d.If you conclude in parts b or c that two of the genes are in fact linked, how would you determine the map distance between them.5.How many different alleles can exist at a given genetic locus? Can three different alleles at the same locus be used to perform a three point cross? Explain your answer.6.Three genetic loci, A/a, B/b, and C/c are all on the same autosome, with B located between A and C.The measured distance from A to B in a two point cross is 10 map units and the measured distance from B to C is 8 map units.The observed interference in a three point cross is 0.5.a.What would be the expected frequency of double crossovers if there were no interference? b.What will be the observed frequency of double crossovers?

c.What will be the frequency of each of the reciprocal double crossover phenotypes?

d.What will be the frequency of each of the reciprocal single crossover phenotypes(a total of four phenotypes).e.What will be the frequency of each of the parental phenotypes? 7.Mutations a and b each cause distinctly different phenotypes.A female Drosophila that is heterozygous at both loci has a wild-type pheontype.When she is test crossed, four types of progeny are produced(wild type, phenotype a, phenotype b, and phenotypes a and b)in numbers that are close enough to equal so that a chi-square test does not reject the null hypothesis for a 1:1:1:1 ratio.There is no difference in phenotype between male and female progeny.When a male of the same initial genotype is test crossed, only two types of progeny are obtained, phenotype a and phenotype b.a.How do you explain the apparent discrepancy between the results of these two test crosses? b.What conclusions can you reach about sex linkage of the two loci? c.What are the phenotypes of the true-breeding parents that were used to produce the original heterozygous females and males used in these two test crosses? d.How would the results have differed for a test cross of the female if both loci had been sex-linked? e.Explain how a double recessive male could be obtained for the test cross in part d(sex linked alleles).8.In test crosses of double heterozygotes, genes A and B yield ambiguous recombination frequencies that suggest possible linkage but do not statistically rule out possible independent assortment.A series of two point crosses(single crossovers)yields the following information: Gene C is 20 map units from Gene A.Gene D is 23 map units from gene A.Gene D is 40 map units from gene C.Gene E is 15 map units from gene B.Gene F is 25 map units from gene B.Gene F is 38 map units from gene E.Gene D is 10 map units from gene F Construct a map showing the relative positions and approximate map distances of all of these genes.a.What is the approximate distance in map units from gene A to gene B? b.How do you explain the ambiguous data obtained in a two point cross of genes A and B.c.Explain how the use of 3 point crosses might have simplified the process of developing your map.Sex Determination, Sex-Linked Inheritance

1.How do the XX/XY sex determination mechanisms differ between humans and Drosophila? How are they similar?

2.Do males of all species have Y chromosomes? Explain your answer.3.Briefly define each of the following and explain its significance to the study of genetics.a.Autosome.b.Homogametic.c.Heterogametic.d.SRY(Sry)e.Sxl

f.Mullerian inhibiting factor g.Hemizygous

4.The human gene that codes for the testosterone receptor is carried on the human X chromosome.a.What biological role does the testosterone receptor play?

b.What are the developmental consequences in an XY human who is hemizygous for a defective testosterone receptor gene?

c.Why is one unlikely to encounter human females who are homozygous for defective testosterone receptors? d.What aspects of normal female development are absent in individuals with testicular feminization and why?

e.Why is it not possible to reverse testicular feminization with testosterone injections? 5.What is a gynandromorph and how is it formed?

6.What is the difference between an X chromosome and a Z chromosome?

7.Can the gene that codes for the testosterone receptor be described as a sex-determining gene? Defend your answer.8.Why is the designation sex lethal(Sxl)not an accurate description of the role of the gene or of its loss of function mutation?

9.Distinguish between monoecious and dioecious in a manner that makes it clear you know what each is and how they differ.10.How does the pattern of inheritance of sex-linked genes differ from that of autosomal genes: a.for recessive alleles? b.for dominant alleles?

11.a and b are two genes located close together on the X chromosome in Drosophila, such that crossing over between them is a rare event that can be ignored for purposes of this problem.Assume that in both cases, wild-type is fully dominant.A female with the genotype aab+b+ is mated with a male of the genotype a+b.a.What will be the genotype and phenotype of male F1 progeny?

b.What will be the genotype and phenotype of the female F1 progeny? c.What will be the genotype and phenotype of male F2 progeny?

d.What will be the genotype and phenotype of the female F2 progeny?

12.Same problem as 4, except assume that a and b are located so far apart on the X chromosome that there is enough crossing over so that they appear to assort independently.However, crossing over does not occur in male Drosophila(and could not in this case anyhow, since there is only one X chromosome).Identify as many classes of progeny as you need to answer the question fully.13.Starting with a white-eyed male Drosophila and a wild-type female, describe the series of crosses that you would have to do to generate a true-breeding population.The white-eyed locus is on the X chromosome.14.You have collected a number of male Drosophila that exhibit numerous different mutant phenotypes.You also have access to a colony of wild-type Drosophila.Summarize the tests you would have to perform to verify that you had a mutant from each of the following categories in your collection.Assume that in every case the mutant flies carry only as many mutant alleles as they need to exhibit the phenotype.a.Sex-linked recessive.b.Sex-linked dominant.c.Autosomal recessive.d.Autosomal dominant that is not lethal when homozygous.e.Autosomal dominant that is lethal when homozygous.Linkage: recombination, map distance

1.Do genes that are carried on the same chromosome always demonstrate linkage? Explain your answer.2.What is a map unit? If two genes are 5 map units apart, what is their recombination frequency? 3.Can alleles of two unlinked genes affect the same phenotypic trait? Explain how you arrived at your answer.4.Can alleles be linked? Explain your answer.5.What is the minimum amount of information that must be provided to describe a diploid genotype? Can you infer anything about linkage from that information? Explain your answer.6.Why is a test cross usually used in preference to production of an F2 generation to measure linkage?

Compensation, Sex-Limited, Sex-Influenced Inheritance

1.What is the Lyon hypothesis and how has its validity been demonstrated?

2.Describe the relationship among the following: Barr body, heterochromatin, late replication, dosage compensation, mosaicism.3.Describe the major differences between dosage compensation in Drosophila and humans.4.Describe three different types of human sex chromosome trisomy.What is the sex in each case? What are the major phenotypic traits in each case? Describe the genetic mechanisms that are responsible for the trisomy in each case.5.Turner syndrome is the only viable human monosomy?

a.How does Turner syndrome arise?

b.Speculate on why individuals with Turner syndrome are viable when all other human monosomies are lethal.14 c.In view of your answer to part b, why do individuals with Turner syndrome enhibit any phenotypicdifferences from normal individuals.6.What is a Barr body and what is its significance?

7.What mechanism makes human aneuploidies that involve sex chromosomes more viable than human aneuploidies that involve autosomes?

8.Propose a possible genetic explanation for each of the following(hint, check pages 424-426 and 539 in the textbook):

A.A human male with two X chromosomes and no Y chromosome.B.A human female with normal testosterone receptors, who has one X and one Y chromosome.C.A female Drosophila with a Y chromosome.D.A male Drosophila with no Y chromosome.E.A human female with three X chromosomes

F.A human male with one X and two Y chromosomes

9.Describe two techniques that have greatly facilitated human karyotypic analysis.10.Describe the aneuploidy that you might expect to find in a male calico cat.11.What would your tentative diagnosis be in each of the following cases: A.A human female with no Barr bodies.B.A human female with one Barr body C.A human female with two Barr bodies, D.A human male with no Barr bodies.E.A human male with one Barr body.12.Briefly define each of the following and explain its significance to the study of genetics.a.Autosome.b.Homogametic.c.Heterogametic.d.Hemizygous e.Sex-limited f.Sex-influenced

13.How will the following differ in a ZZ/ZW system, compared to an XX/XY system? a.Which will be the homogametic sex in each?

b.Which sex will exhibit hemizygous expression of recessive genes in each?

c.Would you expect large numbers of essential genes to be carried on the W chromosome? Relate your answer to the Y chromosome.15 d.If a male is heterozygous for a Z-linked trait, how will it be expressed in his female progeny.e.Describe a comparable phenomenon in an XX/XY system.14.Distinguish among traits that are sex-linked, sex-limited, and sex-influenced.15.Explain how the use of attached X stocks of Drosophila allows direct trnasmission of X-linked mutations from father to son.Chapter 5 Chromosome Mutations: Chromosomal Changes, Monosomy, Trisomy，Polyploidy, Structural Changes

1.Distinguish between the following pairs in a manner that makes it clear that you know what each is and how they differ.a.Euploid and aneuploid b.Triploidy and trisomy

c.Autopolyploid and allopolyploid d.Hybrid and allopolyploid.e.Diploid and amphidiploid f.Homologous and homeologous.2.Why are allotetraploids more likely to be fully fertile than autotetraploids?

3.Describe a process for the experimental generation of a fertile allotetraploid from a sterile cross-species hybrid.4.Does the chromosome number of an allotetraploid have to be an even multiple of four? Explain your answer.Would your answer be different for an autotetraploid?

5.What is the agricultural significance of allopolyploids?(You should be able to think of more than one answer).6.Describe two distinctly different reasons why triploid plants may be preferred for certain agricultural crops.7.A fertile allopolyploid plant with a chromosome number of 38 is crossed with one of its parent species.Do you expect the progeny to be fertile? Explain your answer.8.Does the formation of an allotetraploid between two plant species insure that the most desirable properties of both will be found in the allotetraploid? Explain the reasoning behind your answer.9.What approach would you use to attempt to construct an allotetraploid from two plant species that are not capable of cross pollination? Describe the steps that are involved.16 10.How does a diploid banana differ from commercially sold bananas? 11.What problems stand in the way of fertility of triploid plants?

12.What features make polytene chromosomes particularly useful for the detection of altered chromosomal structure?

13.Where other than a polytene chromosome could one look to verify the existence of a chromosomal inversion or partial duplication? 14.Define the following terms a.Dicentric chromosome b.Tandem duplication c.Pseudodominance d.Paracentric inversion e.Unequal crossing over.15.Deletions, duplications and inversions all cause the formation of loops in polytene chromosomes.How would you distinguish among these three possibilities cytologically? What genetic traits would you look for to support your conclusions?

16.Describe the mechanisms that lead to the production of Doublebar progeny from crosses of males that are hemizygous for Bar eye with females that are homozygous for Bar eye.17.An inversion loop is more likely to cause severe problems during meiosis than a deletion loop.Explain the difference.18.Under what conditions is a duplication of genetic material not abnormal?

19.What special property distinguishes a deletion mutation from a typical missense point mutation(one that codes for the wrong amino acid)?

20.Explain how a deletion mutation can cause partial hemizygosity.21.What type of chromosomal change is particularly likely to result in a dominant phenotype with lethality in the homozygous state.What mechanism is likely to be involved in the lethality.22.Are all seedless fruits triploid? Explain your answer.Chapter 6 Genetics in Bacteria and Bacteriophages 1.Describe four distinctly different ways in which genes can be transferred into a bacterial cell.2.What is the shape of the linkage map of E.coli? How has this been shown? 3.What is the difference between an F+ strain and an Hfr strain? Which is the most useful in bacterial genetic analysis and why?

4.What units are normally used to measure map distances in E.coli ? What is the basis for use of this particular type of unit?

5.What is a merozygote and what is its value in genetic research?

6.What type of bacterial mating system is used to generate stable partially diploid cells? 7.How does genetic transduction differ from transformation?

8.What was the nature of the first experimental evidence showing that DNA was capable of carrying genetic information?

9.What is an auxotrophic mutation? What term is used to describe the corresponding non-mutant state?

10.Explain how the inability to utilize a particular substrate can be used as a genetic marker in bacteria.11.The E.coli genome has been completely sequenced.a.How large is the genome of E.coli?

b.How many times as large is the human genome compared to that of E.coli.(The human haploid genome contains about 3.0 x 109 base pairs).c.How many potential protein-coding genes are contained in the E.coli genome(see table 7.3).d.If the human genome contained a comparable density of genes per amount of DNA, how many genes would be in the human genome?

e.A recent(1999)news report suggested that the number of human genes could be as large as 140,000(significantly higher than previous estimates of less than 100,000).What can you conclude about the density of genes in human DNA relative to that in E.coli DNA?

12.Describe a selective medium scheme for isolation of each of the following types of mutations.a.a leucine auxotroph

b.a strain unable to utilize lactose

c.a strain that is resistant to ampicillin(an antibiotic)

d.a strain that is resistant to infection by a specific type of bacteriophage.e.A cell from a strain auxotrophic for leucine that had been transformed to prototrophy with purified DNA from a proptotrophic strain.13.In many cases, Hfr conjugation can transfer several bacterial genes to a recipient cell without the recipient cell becoming an Hfr cell.Explain how this can happen.18 14.Explain how merozygotes can be used for complementation studies.Be sure that your answer makes it clear that you understand what complementation is.15.Distinguish between lytic and lysogenic bacteriophage infections in a manner that makes it clear that you understand what each is and how they differ.16.Distinguish between specialized transduction and generalized transduction in a manner that makes it clear you know what each is and how they differ.17.What is the smallest known genome size for a free-living organism? How many protien coding units does it contain?

18.Distinguish between virulent and temperate bacteriophages in a manner that makes it clear that you know what each is and how they differ.19.Explain how different genotypes can cause bacterial cells to exhibit similar phenotypes.20.You have a collection of mutant strains of E.coli that are auxotrophic for histidine.After you complete an experiment demonstrating the histidine requirements of these strains, you leave the petri dish cultures on the laboratory bench for a few days.When you return, you discover that there is now growth in the histidine-free control dish for one of the strains, but not for the others.How would you explain this observation?

Chapter 7 Gene expression and Control Genetic Fine Structure: Tetrad Analysis, Complementation, Cistrons

1.Briefly describe two experimental systems in which all of the products of a single meiosis can be recovered.How are such systems used in genetic analysis?

2.Explain how the centromere is used as a genetic marker when analyzing patterns of crossing over in Neurospora

3.What are the major differences in life cycles between the two types of yeast that are widely used in genetic research?

4.What is meant by the term “tetrad” and why is tetrad analysis of importance in genetic research? 5.Distinguish between ordered and unordered ascospores and explain how each can be used in genetic research.6.Explain how a single crossover can generate either a 2:2:2:2 pattern or a 2:4:2 pattern in the ascospores of Neurospora.7.Briefly describe the life cycle of Saccharomyces cerevisiae and explain how it can be used for tetrad analysis.8.Why is a tetratype with four different types of spores a more common occurence than a non-parental ditype, which has only two different types of spores?

9.What are the advantages of doing tetrad analysis with Neurospora ? What are the limitations of such studies?

10.What special values does tetrad analysis bring to genetics.What can be done with it that cannot readily be done with Drosophila or peas?

11.Describe the process of formation of a plaque by bacteriophage.12.How is genetic linkage studied in bacteriophage?

13.What properties make bacteriophage such a powerful tool for recombinational analysis? 14.Describe the phenomenon of complementation as it occurs among various rII mutations in bacteriophage T4.15.Explain why complementation studies cannot be done with dominant mutaitons.16.Bacteriophage mutations A and B do not complement each other when tested in a recombination-deficient strain of bacteria.However in strains that support recombination, there is occasional restoration of function.Explain how this can happen.(You will need to do some reasonable extrapolation beyond what has actually been presented to answer this.)

17.How can complementation studies be done in various types of organisms that normally have only a single haploid genome.(You should be able to come up with several examples from different organisms).18.What is meant by the term cistron? What is the origin of the term?

19.Does complementation between two mutant strains prove that both mutations have occurred within the same biochemical pathway? Explain your answer, including any restrictions you have placed on definitions of terms that you use.20.How can you distinguish whether restoration of function by coinfection with two mutant bacteriophage is due to complentation or recombination?

21.What would you do to analyze the frequency of recombination between two mutant strains of bacteriophage that complement each other?(This calls for some projection beyond what has been covered in class, but should be possible to answer based on what you have been told about complementation and about recombination).22.Cite an example of complementation in a diploid organism.What F2 phenotypic ratio is expected when mutant strains that exhibit complementation are crossed?

23.Can recombination occur within the coding unit for a single protein? Cite evidence to justify your answer.24.Can complementation occur within the coding unit for a single protein? Cite evidence to justify your answer.25.Explain how deletion mapping can be used for preliminary placement of previously unstudied mutations within a particular portion of a cistron.26.Briefly summarize the process of gene conversion, including how the Holliday model of genetic recombination explains its occurence.27.Briefly describe each of the following, including where it is likely to be observed: a.Sister chromatid exchange b.Mitotic crossover

c.Complementary gene action d.Complementation e.Non-parental ditype

Prokaryotic gene expression: lac operon

1.Draw a diagram showing the arrangement of the genetic sites that are involved in the lac operon and briefly summarize the role of each site.2.Starting with lactose in the extracellular environment, describe all of the steps that must occur to induce enhanced expression of the genes in the lac operon.3.What effect will each of the following have on induction of the lac operon by lactose in a medium that lacks glucose?

a.A mutation that inactivates beta-galactosidase.b.A mutation that inactivates galactoside permease.c.A mutation that makes the lac repressor protein incapable of binding to the lac operator site.d.A mutation that makes the lac operator site incapable of binding the lac repressor protein.e.A mutation that makes the lac repressor protein incapable of binding allolactose.4.What advantage is provided to E.coli by the presence of two separate regulatory mechanisms for the lac operon, with one responsive to glucose and the other responsive to lactose? 5.What is meant by a polycistronic transcript, and how is it related to the lac operon?

6.What is the normal function of the operator site and what is the effect of loss of that function?

7.What is the catabolite activator protein(CAP)and how does it affect gene expression at the lac operon?

8.What are the minimum set of components that must be present to have an operon? 9.What is a merozygote and how is it used to analyze the control mechanisms of an operon? 10.What is meant by cis and trans when these terms are used to describe regulatory mechanisms within an operon.Give an example of a mutation that is cis-dominant and one that has dominant effects both cis and trans.11.Describe two different roles of beta-galactosidase and explain the importance of each in the overall function of the lac operon.12.Explain how the presence of glucose in the external environment represses transcription of genes in the lac operon.13.What is the advantage of using an artificial inducer, such as IPTG, to study the regulation of the lac operon?

14.An engineered F' plasmid carrys a lac operon that is fully functional and intact except that each of its 3 enzymes have been mutated in ways that allow them to be distinguished from host enzymes, but do not affect their enzymatic activity.What will be the effect of adding that plasmid to each of the following mutant strains of E.coli ? Include in your answers a description of the properties of the mutant strain without the plasmid and a description of the ways in which those properties are changed by addition of the plasmid.a.An operator constituitive(Oc)strain whose operator is incapable of binding the repressor protein.b.A strain with a non-functional repressor protein(I-)that is incapable of binding the operator.c.A strain with a mutation that renders beta-galactosidease nonfunctional(lac Z-).d.A strain with a mutation that renders the lactose permease nonfunctional(lac Y-)

e.A strain with a mutation in the repressor protein that renders it incapable of binding allolactose or IPTG, without altering any of its other funcitons.15.Is the Lac I gene that codes for the lactose repressor protein considered to be part of the lactose operon? Explain your answer.Tryptophan operon, tryptophan attenuator，1.Distinguish between induction and repression in a manner that makes it clear that you know what each is and how they differ.(Be careful, this is a tricky question that needs to be approached at multiple levels).2.Describe two distinctly different ways in which the trp operon is controlled by the overall availability of tryptophan.22 3.How does the interaction between the repressor protein and the operator site differ between the lac operon and the trp operon? What role does the ligand that binds to the repressor protein play in each case?

4.Describe the mechanism responsible for shutdown of the trp operon when a plentiful supply of free tryptophan is available.5.Describe the mechanism by which the leader-attenuator region fine tunes the extent of transcription of the structural genes in the trp operon when the availability of tryptophan is marginal.6.The leader-attenuation system utilizes a conditional transcription termination signal.Explain how that signal is activated and deactivated.7.Leader-attenuator mechanisms have been found to control operons coding for enzymes involved in the synthesis of a number of different amino acids in various bacterial species, sometimes as the only regulatory mechanism.What do you consider to be the most likely reason for failure to find similar regulatory mechanisms controlling rates of synthesis of other types of biologically important molecules, such as vitamins and nucleic acid bases?(This requires analysis beyond the level of information that has been presented in class, but will be very obvious once you realize what the correct answer is.)

8.Would it be possible to reverse positions, placing the leader/attenuator sequence upstream from the promoter/operator sequence of the trp operon? Explain the reasoning behind your answer.9.Some operons are controlled only by a leader/attenuator mechanism.Does this indicate that the trp operon in E.coli could function normally with the promoter/operator sequence completely removed? Explain the reasoning behind your answer and think carefully about what you are saying..10.What effects on control of the trp operon would you expect from a frameshift mutation resulting from addition of one base in each of the following locations? In each case, would you expect the mutant strain to be able to multiply in a medium that did not contain tryptophan, and would you expect the operon to be turned off in the presence of an adequate amount of tryptophan? a.Near the 5'-end of the coding sequence for the trp repressor protein.b.Near the 5'-end of the coding sequence for the trp attenuator peptide.The codon for tryptophan is UGG, and the complete coding sequence for the attenuator peptide, including the UGA stop codon is 5'-AUGAAAGCAAUUUUCGUACUGAAAGGUUGGUGGCGCACUUCCUGA-3'(Consider this one carefully--it could get complicated!).c.Near the 3'-end of the coding sequence for the trp attenuator peptide(beyond the trp codons).(This one could also get complicated).d.Near the 5'-end of the trp E gene(the first structural gene in the operon).23 e.How would the answer to part b differ if the mutation were a missense mutation in the second codon of the attenuator peptide?

11.A strain of bacteria is auxotrophic because of a missence mutation in the trpE gene(the first one in the operon).Explain the reasoning behind your answers to each of the following questions.a.What effect would this have on the the ability of the strain to grow in a medium containing tryptophan?

b.What effect would this have on the the ability of the strain to grow in a medium lacking tryptophan?

c.Would you expect the trpA gene to be transcribed in this strain when tryptophan is absent from the culture medium?

d.Would you expect the trpA gene to be trainscribed in this strain when the culture medium contains tryptophan?

e.Would you expect the trpE gene product to be translated in a medium lacking tryptophan?(Be careful, this one is tricky).12.As illustrated in figure 8.14, The trpA and trpB gene products are needed only for the final step in tryptophan synthesis in E.coli, namely conversion of indole-3-glycerol phosphate(InGP)to tryptophan.The other three genes in the trp operon are involved in steps leading to the synthesis of InGP.Explain the reasoning behind your answers to each of the following quesitons.a.In a wild-type(non-mutant)strain, what effect would you expect the presence of InGP in a culture medium that contained no added tryptophan to have on transcription of the trp operon

b.Would you expect a strain with a loss-of-function mutation in trpE to be able to grow in a medium that contains InGP but no tryptophan?

c.What would be the transcriptional state of the trp operon in question b?

d.Would you expect a strain with a loss-of-function mutation in trpA to be able to grow in a medium that contains InGP but no tryptophan?

e.What would be the transcriptional state of the trp operon in question d?

13.The gene coding for the tryptophan repressor protein is at a remote location relative to the tryptophan operon.What effect would complete deletion of the repressor gene have on the response of the operon to varying levels of tryptophan in the environment?

14.What effect would an operator constituitive mutation(unable to bind the repressor protein)have on the response of the tryptophan operon to varying levels of tryptophan in the environment?

15.What effect would you expect complete deletion of the leader-attenuator sequence from the tryptophan operon to have on its response to varying levels of tryptophan? Eukaryotic transcriptional control

A few questions covering earlier lectures have been included here to review the background needed for this lecture.1.Dinstinguish among the three types of eukaryotic RNA polymerases in terms of the function of each.2.What are the major differences in organization between prokaryotic and eukaryotic genes.3.Summarize the modifications that must be made in a transcript produced by RNA polymerase II before it can be translated.4.Explain why more complex controls over gene expression are needed in multicellular eukaryotic organisms than in prokaryotic organisms.5.What are the features that distinguish enhancer sequences from functional parts of the basic promoter, such as the CAAT box and the TATA box?

6.How is a distant enhancer site believed to activate transcription?(What mechanism allows it to exert its effect over a considerable distance?)

7.Identify the three different domains that a protein must possess as a minimum to function as a ligand-responsive transcription factor(for example, a steroid hormone receptor).What role is played by each of these domains?

8.Describe the regulatory mechanisms that allow the budding yeast, Saccharomyces cerevisiae to turn on genes for galactose utilization when galactose is available.9.The GAL4 binding site in yeast is commonly referred to as an upstream activating sequence(UAS).Does it satisfy all of the criteria of an enhancer site? Explain your answer.10.Describe the sequence of events that results in expression of the genes that are needed for galactose utilization in yeast.Be sure to identify the regulatory protein that galactose interacts with and the way in which it triggers the gene expression process.11.What are three major types of transcription factors(classified in terms of their DNA-binding domains)?

12.What two types of domains must a protein possess to be a transcription factor? Discuss the relative specificity of each.25 13.What role does the GAL80 protein play in the control of galactose utilization genes in budding yeast?

14.What effect would you expect from a mutation in the GAL4 protein that rendered it incapable of binding to the GAL80 protein?

15.What effect would you expect from a mutation in the GAL80 protein that rendered it incapable of binding galactose?

16.Dnguish between each of the following pairs in a manner that makes it clear you know what each is and how they differ.a.Activator and coactivator

b.Enhancer and upstream activating sequence

c.Hormone response element and steroid hormone receptor d.General transcription factor and activator e.Cytosine and 5-methyl cytosine

17.The frequency of CG sequences in eukaryotic genomes is lower than expected based on the CG content of the DNA of each species and an assumption of random occurrence of all possible dinucleotide sequences.a.Describe a modification of CG base pairs that occurs more frequently in inactive parts of the genome than in actively transcribed genes.b.Describe a mutational process that could preferentially convert CG sequences to other sequences in the genetically inactive portion of the genome.(You may need to go back to lecture 6 for the answer).c.How would you explain the failure of DNA repair mechanisms to reverse the preferential loss of CG sequences?

d.How is the DNA modification from part a retained when DNA replicates?

e.What is the evidence that the modification in part a acts indirectly to inhibit transcription of inactive genes(see boxed example 8.4 if you are having trouble with this one).18.Activation factors and basal transcription factors such as the TATA binding protein are able to recognize specific nucleotide sequences within double stranded DNA.(You may want to look at figure 2.11 while answering this set of questions--note that the top of each base pair as drawn corresponds to the major groove).a.Explain how protein molecules, which tend to be bulky molecules, are able to detect differences in nucleotide sequence in various regions of a double-stranded DNA molecule.b.What features of an AT base pair are seen in the major groove? c.What features of a GC base pair are seen in the major groove?

d.An AA sequence or an AT sequence would result in the same two base pairs being next to each other in the double helical DNA.How do you think a DNA binding domain is able to distinguish between the two?(This will require a bit of speculation).e.What mechanism is commonly employed by transcription factors and activator proteins to read palindromic sequences, such as typical hormone response elements?

Chapter 8 Gene Engineering and Genomics and Proteomics Restriction endonucleases, vectors, Recombinant DNA

You will need to use the table of restriction endonuclease cut sites in the lecture 14 notes to answer some of these questions.You do not need to memorize the cut site sequences for the examination.1.Restriction endonucleases are widely used in recombinant DNA research.a.Distinguish between exonuclease and endonuclease in a manner that makes it clear you understand what each is and how they differ.b.What are the characteristic features of a target site for cutting by a restriction endonuclease? c.What range of frequencies of cutting is encountered with the various restriction nucleases that are currently in widespread use?

d.What is the size of the restriction endonuclease recognition site that is most useful for routine gene cloning operations? Explain the reasoning behind your answer.e.What is a sticky end and why is it considered useful in gene cloning?

2.The frequency with which a particular restriction endonuclease can be expected to cut a random DNA is influenced by the overall base composition of the DNA.a.What effect does the overall base composition of a DNA sample have on the average fragment length obtained with a restriction endonuclease?

b.Will the effect in part a be the same for every restriction endonuclease? Explain the reasoning behing your answer

c.The cut site for Eco RI is G|AATTC.What average fragment lengths do you expect to be produced from DNA with each of the following fractions of GC base pairs? 1/4, 1/3, 1/2, 2/3, 3/4 d.Describe a situation in which the shortest restriction fragments would be obtained with a DNA that was 50% A+T.e.Would you expect Sma I(CCC|GGG)to be able to cut DNA that is 50% AT? Explain your answer.f.Among the enzymes on the list in lecture 15 that have cut sites consisting of 6 nucleotide pairs, which would you expect to yield the largest DNA fragments from a GC-rich DNA and why? 3.Distinguish between 5'-overhangs and 3'-overhangs and describe a hypothetical(or real)example of each.4.What role do restriction endonucleases play in nature?(What were they good for before molecular biologists discovered how useful they can be in recombinant DNA studies?)

5.Do different restriction endonucleases ever generate sticky ends that are the same? Explain your answer.6.Eco RI cuts its GAATTC target site between G and A.A hypothetical enzyme Hyp I cuts the same sequence between T and C.Both enzymes yield sticky ends with the sequence 5'AATT3'.a.What problems would be encountered trying to rejoin the ends of DNA fragments cut with these two enzymes? Use a diagram to explain your answer.b.Can you think of any clever methods to overcome the problems described in your answer to part a? Using the same enzyme to cut both fragments is not an available option.c.Identify an actual pair of enzymes from the list in the lecture 14 notes that have a relationship to each other comparable to the relationship between Eco RI and Hyp I described in part a.7.What prevents restriction endonucleases from destroying the genomic DNA of the bacteria that produce them?

8.A DNA fragment prepared with Bgl II was successfully cloned into a vector that had been cut with Bam H1.a.What property of these two enzymes made it possible to perform this cloning without problems.b.It was subsequently discovered that neither of the original enzymes would release the cloned DNA from the vector.Explain why this occurred.c.Would it be possible to use Mbo I to release the DNA from the vector? Explain what problems might be encountered.d.If the Bam HI site were located in the middle of a multicloning site(polylinker), would you expect to be able to release the cloned insert with a different restriction endonuclease than those used in cloning? Explain your answer?

e.What procedure could you use to release the cloned insert in part d? What additional problem(s)would you then have to overcome?

9.What is a vector?(Be careful not to define vectors too narrowly).10.What is the value of using plasmids that carry antibiotic resistance genes as vectors?

11.What is the value of inserting a cloned DNA sequence into the middle of an antibiotic resistance gene?

12.Replica plating was an extremely valuable technique in early gene cloning studies, but is no longer as widely used.a.Describe the processes involved in replica plating.b.Explain the value of replica plating in the early studies.c.What has been done to eliminate the need for replica plating?

13.What is the rationale for the inclusion of multiple cloning sites in modern cloning vectors.Include in your answer a description of what multiple cloning sites are.14.Describe a cloning technique in which both the cloning vector and the bacterial strain that it is infected into have been engineered to work together to facilitate the process of screening.15.What is the rationale for using two different restriction endonucleases to prepare a DNA fragment for cloning.(You should be able to think of at least two different answers.)

16.You are trying to clone a gene by ligating Eco RI fragments into a plasmid vector.You get some successful clones, but sequencing studies reveal that you have only half of the coding sequence because there is an Eco RI restriction site in the middle of the gene.What would you do to obtain a full length clone of the gene?

17.You are trying to clone a gene, but have been unsuccessful in finding any restriction endonucleases that do not have cut sites within the gene.What alternatives are available to you? 18.Describe the selective steps that you would use to identify bacteria containing pBR322 plasmids carrying cloned DNA inserts that were originally ligated into plasmids that had been linearized with Bam HI

19.How would your answer to question 18 differ if the cloning had been done with Pst I? 20.Explain how it was possible to insert a polylinker into the 5'-end of the beta-galactosidase gene without losing biological function.Also explain why biological function is lost when a DNA fragment is ligated into a cut polylinker site.21.Why would you normally not use restriction endonucleases with four or eight nucleotide cut sites for cloning into plasmids?

22.Identify two different pairs of isoschizomers in the list of restriction endonucleases in the lecture 14 notes.In each case, how do the actual cuts differ from each other.23.Explain the value of having two different kinds of selection engineered into a plasmid for DNA cloning.What role is played by each?

24.You have a preparation containing DNA fragments prepared by digestion with Not I.Assuming the original DNA is 50% GT, how many pieces would you expect the average fragment in that preparation to be cut into by Eco RI? By Alu I?

Vectors for large inserts, cDNA, libraries, probes, expression vectors

1.What are the advantages of using each of the following vectors as alternatives to plasmids? a.Lambda-phage(Charon)vector.b.Cosmid

c.M13 viral vector

d.Yeast artificial chromosome.e.Bacterial artificial chromosome.2.How can site-directed mutagenesis be achieved in a cloned cDNA sequence? Include in your answer a description of the type of vector that you would have to use and the way in which you would transfer the cDNA clone from its original vector to the vector used for site-directed mutagenesis.3.Site-directed mutagenesis has become a valuable tool in molecular biology.a.Use the table of codons in figure 4.4 or inside the front cover of the textbook to generate a DNA code for a protein with the following partial sequence: Met-His-Leu-Val-Pro-Gly-Val-trp-Ile-.......b.Describe in detail how you would use site directed mutagenesis to change the proline to serine.4.Expression vectors are widely used in recombinant DNA technology.a.What is an expression vector? Include in your answer the special properties that a vector must have to function as an expression vector.b.Describe as many different reasons as you can why it may be useful to clone a gene or a cDNA into an expression vector.c.What are the potential advantages of using an expression vector with a strong constituitive promoter?

d.What are the potential disadvantages of using an expression vector with a strong constituitive promoter?

e.How can the disadvantages that you described in question 2 be avoided? 5.What is a genomic library and what is its value?

6.cDNA clones are widely used in recombinant DNA studies.a.What does the term “cDNA” stand for? b.How is cDNA prepared?

c.What features of cDNA make it a useful research tool?

d.What are the limitations that restrict the usefulness of cDNA clones?

e.Would you expect an eukaryotic cDNA to work well in a prokaryotic expression vector? Explain the reasoning behind your answer.7.You have a polyclonal antibody to a protein.You would like to clone the coding sequence for the protein.How would you go about it?

8.Explain the rationale for using IPTG rather than lactose or allo-lactose to induce expression of genes cloned downstream from the lac promoter/operator sequence.9.You have the cloned cDNA for a protein.Describe the procedures you would use to isolate a clone that contains the genomic sequence from a genomic library contained in lambda phage vectors.10.Do you expect cDNA preparations to contain cut sites for restiction endonucleases? Explain your answer.30 11.An unaltered vector and the same vector containing a cloned cDNA are denatured in the same solution, allowed to anneal slowly, and prepared for electron microscopy.What would you expect to see with the electron microscope?

12.What is a degenerate probe and what is it used for? In designing such a probe, what problems are likely to be encountered and how can they best be overcome.13.You know the amino acid sequence of a protein.Starting with a preparation of messenger RNA from a tissue that makes large amounts of the protein, how would you go about isolating a cloned cDNA that contains the nucleotide coding sequence for that protein? You should be able to think of two quite different approaches to this question.14.Why is it sometimes desirable to reduce the stringency of probe hybridization reactions? 15.What is meant by the term “restriction map”? What is the value of using partial digests in such mapping?(You may need to go back to lecture 14 for this and the next question)16.What is the advantage of preparing a restriction map with more than one restriction endonuclease?

17.You have used a CDNA to isolate a series of clones of various sizes from a genomic library that was prepared by incomplete digestion with Eco RI.Explain how you might use restriction mapping to determine patterns of overlapping among these clones and to assemble a set that collectively contain the complete genomic sequence including the introns that were spliced out of the mRNA used to prepare the cDNA.Also explain how you could identify presumptive promoter sequences located immediately upstream from the start of transcription.This question will require you to do some projection beyond specific details that we have covered in class, but should be fully answerable with the information that has been presented to you at various times during the semester.18.Using the table of codons in the textbook, identify all possible amino acid sequences whose genomic coding sequences could generate a cut site for EcoRI(G|AATTC).(Be sure to examine all possible reading frames and exclude all nucleotide sequences that could not be found in the coding sequences for proteins.)

19.In an organism whose DNA is 50% AT, how long would a protein have to be to have a 50% chance of containing a cut site for EcoRI within its coding sequence? 20.Vectors derived from bacteriophage lambda have become quite popular.a.Describe the modifications that are made in bacteriophage lambda to generate a typical vector(such as the Charon vectors)

b.Explain how blue-white selection is used to identify lambda vectors that contain cloned inserts.c.What determines the size range of inserts that can be cloned in a lambda phage vector?

d.What is done to prevent lambda phage vectors from entering into a lysogenic relationship with their host bacterial cells.e.What special modification is likely to be needed in order to clone a typical cDNA in a lambda

phage vector?(You have not been given an answer for this question, but you should be able to figure it out, based on what you are supposed to know about cDNAs and lambda phage vectors).PCR, Southern, Northern, Western blots

1.The polymerase chain reaction(PCR)is a widely used technique in molecular genetics.a.What special property must be possessed by the DNA polymerase used in PCR, and why is this so important for doing PCR?

b.Explain the use of primers in PCR, including why two different primers must be used.c.What relationship must exist between the two primers used in PCR?

d.Summarize all of the components that must be present in a PCR reaction mixture.e.Summarize the overall process that makes possible extensive amplification of specific DNA sequences with minimal effort through the use of PCR.2.One of the ways of determining whether a sequence has been successfully amplified by PCR is to do electrophoresis and look for a band of DNA of sharply defined size.Explain how such a band arises during PCR.3.Why is it not necessary to add new DNA polymerase and primers for each new cycle of PCR? 4.You have a cDNA of unknown sequence in a plasmid vector.How could you do a PCR amplification of the cDNA without first determining its end sequences?

5.What types of precautions must be taken when doing PCR to be certain that the desired results are obtained?

6.What aspects of PCR make it particularly useful in forensic investigations? How do the same properties make PCR particularly susceptible to challenge by defense lawyers?

7.Distinguish between Southern and Northern blots in a manner that makes it clear you know what each is and how they differ.8.How does a Western blot differ from both of the above? When is a Western blot used in perference to a Northern or Southern blot?

9.You have a cloned cDNA for a protein.You want to find a restriction endonuclease that can be used to isolate the genomic coding sequence in a single DNA fragment.Describe the procedures you would use to identify an appropriate restriction endonuclease.(Assume that you are dealing with an eukaryotic gene that contains introns of unknown sequence).10.You have a full length cDNA that codes for an eukaryotic protein.The cDNA was cloned using Pst I.When you do a genomic Southern blot with Eco RI, you detect three bands of distinctly different sizes that hybridize with the cDNA probe.32 a.What are two very different possible interpretations of the data?

b.Describe the additional experiments that would be needed to distinguish clearly between the two possibilities.(Be aware that there are multiple possible ways of approaching this problem, and list as many as you can).11.Why is it generally desirable to use a relatively small probe when doing a Southern blot.What situations may make the use of a larger probe desirable?

12.Summarize the major steps that are involved in Southern blotting.13.Describe a procedure that could be used to determine which tissues in a rat express the highest levels of a particular gene.What is the procedure called? What is the origin of the name? 14.Explain how it is possible to separate proteins by size alone, by isoelectric point alone, or by a combination of isoelectric point and size.15.What result would you expect to see if you probed a Southern blot of a PCR product derived from genomic DNA separately with each of its primers? How might the results differ if different restriction endonucleases were used on the PCR product prior to running the Southern blot(this calls for some speculation--explain any assumptions that you have made in arriving at your answer.16.What is a dot blot and when would you be most likely to use it?

17.You have a full-length genomic clone for an eukaryotic gene.You isolate and purify the cloned insert and use it as the starting point for a Southern blot of the clone.Using a cDNA for the gene as a probe, you detect five bands on the Southern blot.However, when you label the cloned genomic sequence and use it as a probe, you see two additional bands.a.Propose an explanation for the additional bands.b.You isolate the restriction fragment that is responsible for one of the additional bands and use it as a probe for a Southern blot prepared the same way as the first one.How many bands do you expect to see? Explain the reasoning behind your answer.c.You purify the cDNA for the gene and do a Southern blot of it using the same restriction endonuclease that was used for the genomic Southern blot.When you probe that Southern blot with the full length cDNA, you only find three bands.Propose an explanation for the reduced number of bands.d.You purify one of the bands from part c and use it as a probe on the genomic Southern blot.How many bands do you expect to detect? Explain the reasoning behind your answer.e.You use the probe from part d on a Southern blot of the cDNA prepared with a different restriction endonuclease.What possible range of results might you see? DNA sequencing

1.Explain the role played by electrophoresis in determining DNA sequences.2.What type of reagent is used to achieve selective chain termination in DNA sequencing studies?

3.DNA sequencing is frequently done with single-stranded DNA as the starting material.a.What are the potential advantages of using single-stranded DNA?

b.Is the use of single-stranded DNA strictly necessary? Explain the reasoning behind your answer.c.What additional step would be needed to start with double-stranded DNA?(You have not been given an exact answer, but you should be able to figure out what must be done.)

d.Would it be possible to do sequencing by adding dideoxyribonucleotide triphosphate chain terminators to a PCR reaction? Explain your answer.e.Would it be possible to use a single PCR primer as a sequencing primer? Explain your answer and discuss any special problems that might be encountered.4.Why is it important to use a polymerase that lacks 5' to 3' exonuclease activity(such as the Klenow fragment of DNA polymerase I)when doing DNA sequencing?

5.You have a series of partial and full length cDNA and genomic clones in vectors that contain polylinker sites.Describe the primers that you would need to determine the entire sequence of the cloned insert and possible alternative strategies that you might use to obtain the complete sequence in each of the following cases.a.The total length of the insert is 350 base pairs.b.600 base pairs.c.1000 base pairs.d.10,000 base pairs.6.Why is it necessary to use four parallel electrophoretic lanes when determining DNA sequence by “standard” methods? How have newer methods eliminated this requirement? 7.Explain how dideoxyribonucleotide triphosphates terminate chain growth.8.What prevents all growing chains from being terminated at the same length?

9.What is an open reading frame and why is its identification important during DNA sequencing? 10.Sanger's early analysis of DNA sequence in the single stranded DNA bacteriophage phi-X174 revealed overlapping open reading frames.What is the significance of this discovery?

11.You are sequencing the cDNA that codes for a particular enzyme in mice.As a check on the accuracy of your procedures, you do sequence analysis on two separate clones both prepared from the mRNA of the same mouse.The two sequences correspond exactly, except at one nucleotide about halfway through the coding sequence, where you obtain a C in one of the samples and a T in the other.a.How would you interpret the data?

b.You transfer both clones to an expression vector, and they both produce equally functional enzyme.What is the most likely explanation for how this can happen?

c.Would you expect to see any differences in the amino acid sequences of the two enzymes? Explain your answer.d.In part b, one of the expression vectors fails to produce a functional enzyme.How would this affect your answers to parts b and c?

e.You have a pair of unique sequence oligonucleotide primers that allow you to use PCR to amplify a sequence 150 nucleotides long that contains the C versus T site, using genomic DNA from the same mouse as your starting material.You then do sequencing on the PCR product, using the primer that hybridizes to the antisense strand as your sequencing primer.What do you expect to see on your sequencing gel at the C versus T site?(Note that this question requires a knowledge of PCR from Lecture 17.It also requires you to extrapolate beyone what you have been told).12.You are sequencing using the sense strand of a cDNA that has been cloned into an M13 viral vector as the template.How does the data that you read from your sequencing gel need to be modified to obtain the correct sequence for the sense strand of the cDNA? What term is used to describe the sequence that you have read from your gel?

13.Why does the sequence you read from the gel in Sanger dideoxy sequencing not begin with the sequence of the primer that you used?

14.What are the advantages of using fluorescent labels rather than radioactive labels for sequencing?

15.When sequencing with a primer for a vector with a multi-cloning site, you encounter the sequence GAATTC at the start of the cloned sequence that you are expecting.Explain how this might happen.16.The RNA coding sequence for the tryptophan operon attenuator peptide(lecture 12)is 5'-AUGAAAGCAAUUUUCGUACUGAAAGGUUGGUGGCGCACUUCCUGA-3'.a.Sketch a sequencing gel showing the sequence that would be obtained if you used the antisense strand of the DNA as the template and a primer that hybridized to the DNA just beyond the end of the coding sequence.b.Same as a, except using the sense strand of the DNA as the template.c.Same as a, except containing a frameshift mutation that causes the formation of a stop codon(UGA)near the middle of the sequence.The stop codon is to be formed by frame-shifting, and not by the direct insertion or deletion of a base at the site of the stop codon.Chapter 9 Gene Mutation DNA repair

1.Thymine dimers are one of the frequent targets of DNA repair systems.a.What is a thymine dimer.b.How are thymine dimers formed?

c.Why is it important to remove thymine dimers from DNA

d.Describe a method that eliminates thymine dimers without removing and replacing DNA sequences.e.Describe as many different mechanisms as you can for removal of thymine dimers from DNA.2.What is excision repair and how does it work? 3.What is mismatch repair and how does it work?

4.What mechanisms are used to distinguish newly made DNA strands from their template strands to be certain that error correction is done on the new strand and not on the template strand when a mismatch is detected?

5.What is the genetic defect involved in the human genetic disease Xeroderma pigmentosum? What limitations does it place on the lives of individuals who have it?

6.How do mutations induced by X rays and ultraviolet radiation tend to differ from each other? 7.Compare the mechanisms used to overcome ultraviolet light-induced damage to DNA in photoreactivation, as opposed to excision repair.8.How is damage to DNA that has been caused by alkylating agents repaired? What is the repair process called? What is the first intermediate step in the repair process?(Hint: you may need to go back to the previous lecture to find the nature of the damage done by alkylating agents)9.Describe the mechanisms that are involved in postreplicative(recombinational)repair.10.What is error-prone repair and under what conditions is it invoked? How can the existence of an error-prone repair system be justified(beyond the fact that it has been observed to occur)? 11.Describe the roles played by the RecA protein in various cellular responses to DNA damage.12.What special mechanisms exist for selective repair of the antisense strands of actively transcribed genes.Why is a comparable level of repair not expected for the sense strands? 13.Describe the last line of defense that a bacterial cell has against ultraviolet damage that is not detected and repaired as soon as it occurs.14.What genetic defect has been associated with Cockayne syndrome in humans.15.Starting with a wild type bacterial cell, what mutations would you select for in order to obtain a 36 strain that could be used to test for mutagens with maximum sensitivity.Chapter 10 Extranuclear Inheritance and Maternal Effect

Extranuclear Inheritance, Maternal Effect

1.What is the effect of a mutation in the bicoid gene in Drosophila?

2)Describe the pattern of inheritance of direction of coiling of the shell of the pond snail Limnea peregra.3.Briefly describe two distinctly different examples of maternal inheritance.4.What is a petite mutation in yeast? What metabolic defect is responsible for the peitite phenotype? 5.Describe three different inheritance patterns of petite mutations in yeast, and explain how each is achieved.6.Distinguish between a neutral petite(rho0)and a suppressive petitite(rho-)in a manner that makes it clear that you know what each is and how they differ.7.How does the pattern of inheritance of genes on the mitochondrial genome differ from that of dominant sex linked genes? Identify a specific pattern that would distinguish between the two.8.What properties make mitochondrial genes particularly useful in the study of short-term evolutionary changes in populations?

9.What conclusions have been drawn from studies on human mitochondrial gene sequences? What problems have caused these conclusions to be viewed somewhat cautiously?

10.What is meant by the term “bottleneck” as it is used in genetics? What are some of the likely causes of bottlenecks? What evidence suggests that a bottleneck may have occurred in human evolution?

11.What properties of modern mitochondria suggest that they may have originated as prokaryotic endosymbionts?

12.Explain the dependence of modern aerobic life forms on mitochondria.13.Describe three distinctly different ways in which uniparental mitochondrial inheritance can be achieved.Based on lectures from earlier in the semester, describe two other ways in which some of the inheritance received by specific individuals can be uniparental.37 14.Paternal imprinting and mitochondrial inheritance will both cause maternally-derived genes to be expressed exclusively in the immediate progeny of a mating.How would you distinguish between the two types of inheritance?

15.What is the presumed evolutionary origin of the genome found in chloroplasts.16.How is a defective chloroplast genome likely to be manifested phenotypically in a higher plant? 17.What is the basis for claiming that cells in higher plants have three separate but interacting genomes?

18.Describe the role played by kappa particles in Paramecium.19.Explain why most cells in budding yeast are homoplasmic even when originally derived from a heteroplasmic cross.20.What reasons may be responsible for the fact that such a high percentage of the genes in a typical mitochondrion code for RNA sequences that are not translated?

Chapter 11 Genetics and Development 1.What characteristics of homeotic gene?

2.Distinguish the role of nuclei cytoplasm in organism development? 3.Explain ABC model in flower development? 4.What is totipotency.Chapter 12 Quantities Genetics Because of time limitations, only questions 1 through 7 were covered in enough detail to be included in the final examination.1.What characteristics of wheat make it particularly useful in studies on quantitative genetics? 2.Distinguish between additive alleles and those that exhibit dominance, and explain how allelic interaction determines phenotype in each case.3.Explain how five different shades of color can be achieved with just two alleles each at two loci.38 4.What characteristics must be possessed by a set of genetic loci in order for the principles of quantitative genetics to be applied to them?

5.How would you determine the theoretical number of different phenotypes and their phenotypic ratios for n different additive genetic loci?

6.What factors usually limit the number of different phenotypes that can be distinguished in polygenic inheritance?

7.What prevents application of the concepts of quantitative genetics to the study of traits that are controlled by dominant and recessive alleles?

Items below this line will not be included on the final examination.8.Describe the difference between discontinuous and continuous variation.9.Distinguish among mean, median, and mode in a manner that makes it clear you know what each is and how they differ.10.How does a distribution with low variance differ from one with high variance? 11.What is the difference between a skewed distribution and a normal distribution? 12.What is meant by the concept of heritability when it is applied to a phenotypic trait that is influenced by polygenic inheritance?

13.Briefly define each of the following and explain its significance.a.Transgressive segregant b.Bimodal distribution c.Hybrid vigor d.Inbreeding depression e.Quantitative trait locus

14.Describe possible patterns of interaction between genotype and environment.15.What factors tend to limit the amount of phenotypic change that can be achieved by selection? 16.What factors do you think are causing average human height to be taller now than a few hundred years ago?(This calls for speculation on your part based on what you should have learned about continuous variation.Also, several different factors may be implicated.)

Chapter 13 Population genetics and Evolution

Population Genetics I

1.What is the basic difference in approach between the Mendelian genetic studies discussed earlier in the semester and the population genetic studies discussed in the current lecture? 2.Write the basic Hardy-Weinberg equations for distribution of alleles in a population and distribution of genotypes in a population, and show how the two are related.3.How can the relationship between allelic frequency and genotypic frequency be depicted visually? Draw an appropriate figure.4.What conditions must be met in order for the Hardy Weinberg relationship to be applicable.5.A rare recessive disease has a frequency of occurrence of X among the children of unrelated parents.a.What is the allelic frequency of the allele that is homozygous in diseased individuals? b.What is the frequency of heterozygous carriers of the disease in the general population? c.What is the frequency of individuals who are neither afflicted nor carriers?

6.What pattern of change of allelic frequencies over time is expected in a large population with random mating and no selective advantage of any of the genotypes?

7.Explain the meaning of the symbols H, P, and Q, and relate each to allelic frequencies p and q.8.Use a diagram to demonstrate how inbreeding leads to loss of heterozygosity.9.What is meant by the term homozygosity by descent?

10.Define the inbreeding coefficient(F)in terms of loss of heterozygosity.11.Use specific equations to show how the frequencies of homozygous genotypes(P and Q)are affected by the inbreeding coefficient.12.What would the inbreeding coefficient be in each of the following cases? a.For the children of a first cousin marriage(parents have the same grandparents).b.For the children of a second cousin marriage(parents have the same great-grandparents)c.For childdren of a marriage in which a grandson of a couple married a great-granddaughter.Assume that the grandson and great-granddaughter were descended from different children of the original couple.(Hint: construct the entire pedigree and determine the dilution of original parental alleles at each reproductive step, taking into account that there is one more generation on one side

than on the other.Don't forget that there are four parental alleles.)(Alternatively, this is a good place to use path distances.)

d.Brother-sister matings of laboratory mice.e.The offspring of the mating of a male laboratory rat with his female progeny(construct a pedigree and determine the dilution of alleles as in question c).13.Alleles A and B are codominant.Calculate the relative frequencies of the three possible phenotypes for each of the following frequencies of A.(Assume that A and B are the only alternatives).a.A = 0.5 b.A = 0.2 c.A = 0.1 d.A = 0.01 e.A = 0.001

14.Allele a is recessive to allele A.Calculate the relative phenotypic frequencies in each of the following situations.(Assume that A and a are the only alternatives).a.a = 0.5 b.a = 0.2 c.a = 0.1 d.a = 0.01 e.a = 0.001

15.What is the highest frequency of heterozygosity that can exist is a population that is in Hardy-Weinberg equilibrium.What are the allelic frequencies that yield the highest fraction of heterozygosity.Hint: If you are not particularly skilled in mathematics, the best approach to this one is trial and error, coupled with a little bit of intuition.(Alternatively, see figure 24.5 in Klug and Cummings, Concepts of Genetics, 5th Edition, Norlin reserve)

16.What changes occur in the Hardy-Weinberg equilibrium when the alleles that are being examined are carried on the X-chromosome?

17.Describe as many different ways as you can in which typical human mating patterns are likely to cause deviations from an idealized Hardy-Weinberg equilibrium.In each case, describe the type of deviation that is expected.18.What aspects of the life cycle of garden peas made it particularly easy for Mendel to obtain true-breeding strains with which to do his experiments?

19.You are working with two independently assorting loci A/a and B/b in garden peas.You deliberately cross true breeding AB peas with true-breeding ab peas.You then grow several generations allowing only self-fertilization, with sufficiently large samples so there is no selection

against rare genotypes.What distribution of genotypes and phenotypes do you expect to emerge? Exact calculations may get too complicated, but you should be able tocome up with some good generalizations.20.You are working with two genetic loci A/a and B/b that are about 10 map units apart on the same chromosome in garden peas.You deliberately do a dihybrid cross of two pure-breeding strains with the recessive alleles in coupling.You then grow several generations allowing only self-fertilization, always working with sufficiently large samples so there is no selection agains rare genotypes.What general patterns of genotypes and phenotypes would you expect to emerge?(You may find it helpful to consult table 15.1b).This is too complex for exact calculations, but you should be able to come up with some reasonable approximations.Also, be sure to take into account the cumulative effects of continued crossing over in successive generations.(Yes, this does call for a lot of speculation!)21.What tentative conclusion would you reach about a population that exhibited a high degree of polymorphism(the presence of alternative alleles at a high percentage of its genetic loci), but a very low level of heterozygosity in its

Population Genetics II

1.What possible explanations can be offered for loss of heterozygosity in certain populations found in the wild?

2.What criteria must be met for a genetic locus to be considered monomorphic? Polymorphic? 3.What is meant by the term “bottleneck” as it is used in genetics?

4.The Northern elephant seal has made a substantial recovery from near extinction.Why are geneticists still worried about its future?

5.Why is a high level of polymorphism in a population considered desirable?

6.What driving forces have caused the allelic frequency of HbS, which causes sickle cell anemia when it is homozygous, to become elevated in Central African populations? 7.What is the relationship between relative fitness and selection coefficient?

8.What is heterozygous advantage and what impact does it have on the population that emerges from an extended selective process?

9.In a population in which there is heterozygous advantage, what determines which of the two alleles that are involved reaches the highest equilibrium frequency?(You may have to make a 42 common-sense extension from what has been presented to answer this one.Think in terms of the relative s values for the two homozygotes.).10.Why does an allele that provides resistance to an adverse environmental condition not always become fully established and essentially monomorphic in a population?

11.Explain how a balance between selection and mutation can establish a constant allelic frequency for a recessive lethal trait.12.Describe two different ways in which reduction of a population to a small size can permanently alter the genetic composition of the progeny of that population, even if their number later increases.13.What are the mechanisms responsible for genetic drift, and how do they differ from founder effects?

14.Explain how an environmental change can alter selection.Illustrate with a real-life example.15.Why is it valuable to have a high degree of heterozygosity in a population?

16.Explain why selection is not very effective in the complete removal from a population of an allele that is deleterious only when in the homozygous recessive state.17.Explain how a disease epidemic can alter the balance of alleles that have nothing to do with resistance to that disease.18.Explain how a pericentric inversion might give rise to disruptive selection, and how such selection might be the first step toward formation of separate species.19.Describe a situation in which selection may not efficiently remove a dominant lethal allele from a population(hint: remember to use the normal definition of a “dominant lethal” allele--it does not mean dominant lethality or it would not exist in the population to start with).population? necessary?

18.What is an embryonal stem cell(ES cell)and what is its special value in genetic research? 19.Describe two different approaches that are being taking toward the use of biotechnology in vaccine production.20.Distinguish between transfection and transformation in a manner that makes it clear you know what each is and how they differ.参考书目：

[1] 《遗传学》第三版 朱军 中国农业出版

[2] 《遗传学》第二版 刘祖洞

上海复旦大学 高等教育出版社 [3] 《遗传学》第一版 刘庆昌 科学出版社

[4] 《Principles of Genetics》Second Edition D.Peter Snustad

University of Minnesota, Michael J.Simmons, University of Minnesota,John Wiley & Sons, Inc.[5]《Essentials of Genetics》Fourth Edition,William S.Klug

The College of New Jersey, Michael R.Cummings

University of lllinois at Chicago高等教育出版社