0  402007  402015  402021  402025  402031  402033  402037  402043  402045  402051  402057  402061  402063  402067  402073  402075  402081  402085  402087  402091  402093  402097  402099  402101  402102  402103  402105  402106  402107  402109  402111  402115  402117  402121  402123  402127  402133  402135  402141  402145  402147  402151  402157  402163  402165  402171  402175  402177  402183  402187  402193  402201  447090 

5.(2010·唐山调研)下图是一个白化病家族的遗传系谱图。请写出Ⅰ1、Ⅰ3的基因型和Ⅲ1为白化病患者的几率                          ( )

A.AA、Aa和1/16       B.Aa、Aa和1/9

C.Aa、AA和1/4        D.Aa、Aa和1/64

解析:白化病为常染色体隐性遗传病,由Ⅱ1、Ⅱ4为患者,可知Ⅰ1、Ⅰ3均为杂合子(Aa),则Ⅱ2、Ⅱ3均可能为AA或Aa,Ⅲ1为白化病患者的概率为××=。

答案:B

试题详情

4.人类的多指(A)对正常指(a)为显性,属于常染色体遗传病。在一个多指患者(Aa)的下列各细胞中,不含或可能不含显性基因A的是                ( )

①神经细胞 ②成熟的红细胞 ③初级性母细胞 ④次级性母细胞 ⑤肌肉细胞 ⑥成熟的性细胞

A.①②⑥         B.④⑤⑥

C.①③⑤         D.②④⑥

解析:染色体基因位于细胞核内,成熟的红细胞没有细胞核;基因型为Aa的性原细胞经减数第一次分裂等位基因分离,产生含A或a两种次级性母细胞;含a的次级性母细胞减数第二次分裂不能产生含A的成熟性细胞。

答案:D

试题详情

3.(2010·湛江质检)根据孟德尔遗传规律推断,下列结构中可能含有等位基因的是  ( )

①四分体 ②姐妹染色单体 ③一个DNA分子的两条脱氧核苷酸链 ④非同源染色体

A.②④         B.只是③

C.①②         D.只是①

解析:等位基因指同源染色体的同一位置上控制相对性状的基因,由此排除③④;四分体是指联会的一对同源染色体,等位基因位于同源染色体上;联会时同源染色体的非姐妹染色单体可能会发生互换,导致姐妹染色单体上有等位基因。

答案:C

试题详情

2.番茄中红果对黄果为显性,把黄果植株花粉授到红果植株(Mm)的柱头上,所结果实的颜色及胚的基因型是                         ( )

A.全部红色,Mm          B.红∶黄=1∶1,Mm或mm

C.全部红黄色,Mm        D.全部红色,Mm或mm

解析:果实各部分起源不同,当年形成的种皮、果皮还是当代母本珠被、子房壁(Mm)发育而成的,胚是受精卵(Mm或mm)发育而成的,所以要想通过果皮、种皮性状来反映胚的基因型,这就必须把这些当年杂交得到的种子再种下去(第二年),然后对长成的植株所结果实的果皮、种皮性状进行统计分析时,就会发现果皮、种皮性状的分离现象反映出来了。所以当年所结果实的颜色仍然全部为红色,而胚的基因型是Mm或mm。(

答案:D

试题详情

1.孟德尔遗传定律只能发生在                      ( )

①真核生物 ②原核生物 ③无性生殖 ④有性生殖 ⑤细胞质基因 ⑥细胞核基因

A.②③⑥    B.②③⑤

C.①④⑥         D.①③⑤

解析:孟德尔遗传定律是指进行有性生殖的真核生物,在通过减数分裂形成配子时,位于细胞核的基因的传递规律。

答案:C

试题详情

One of South Korea’s most famous actresses was found  1  in her home on Thursday in what the police called a suicide.They linked her death to hateful online  2 ,a growing social problem in South Korea,which has one of the world’s most active online communities and one of its highest  3  rates.

The body of the actress,Choi Jin­sil,39,was found in the bathroom of her  4  with a rope made out of bandages around her neck.

Already struggling with a messy divorce,she had been deeply troubled by online accusations that she had  5  another actor to kill himself in his car a month earlier.The actor,Ahn Jae­hwan,was struggling with  6 ,and the rumors said she had pressed him mercilessly to repay money she had  7 .She complained to the police about the rumors,which she called  8 ,and they were  9  when she died.

The night before,according to the police,she came home drunk and  10  before her mother,crying and bitterly  11   the Internet rumors.Then Ms. Choi sent cellphone text messages to her makeup assistant,asking her to look after her two children.Almost 80 percent of South Korea’s households have broadband  12 ,bringing  13   active online interactions.Most Web sites here have bulletin boards  14   users can post unchecked,anonymous  15  ,and nearly all young people run their own blogs,updating  16   cellphone.

Major Web sites have in recent years doubled the number of monitors to screen out __17__ character assassination and  18   more quickly to complaints of hateful rumors.But many victims still complained that vicious rumors spread so fast their reputations were  19   virtually overnight.

When two young female celebrities killed themselves last year,at least one of them,the singer Yoo Na,was found  20   from hateful online rumors saying she had had plastic surgery.

[解题导语] 年底将年满40岁的崔真实10月2日凌晨被发现在家中浴室死亡。据韩国媒体报道,离婚后长期饱受抑郁症之苦的崔真实最近遭受“因借高利贷给男演员安在焕”传言的困扰。此前,崔真实还经常向朋友抱怨生活辛苦,担心自己人气下滑。

1.A.awake  B.asleep  C.dead  D.sick

解析:从suicide一词可以判断是死在家中。

答案:C

2.A.rumors  B.news  C.reports  D.articles

解析:后文(第三段)提及崔真实逼死安在焕的谣传,故选rumor。

答案:A

3.A.death  B.accusation  C.suicide  D.crime

解析:联系全文所叙可知此处指自杀率,用suicide。

答案:C

4.A.hotel  B.apartment  C.building  D.company

解析:由首句知崔真实死于家中,选项四个词之中与home最接近的是apartment。

答案:B

5.A.made  B.forced  C.driven  D.caused

解析:由下文所叙可知,此处指崔真实迫使另一位男演员自杀,drive sb. to do sth.“驱使/驱动某人做某事”。

答案:C

6.A.poverty  B.illness  C.debt  D.divorce

解析:由下文谣言说崔真实曾无情地逼迫他还钱可知,他债台高筑。选debt。

答案:C

7.A.lent  B.paid  C.borrowed  D.charged

解析:逼迫他还的钱当然是她曾借给他的,lend sb. money“借给某人钱”。

答案:A

8.A.true  B.baseless  C.helpless  D.reasonable

解析:崔真实向警察抱怨是因为她觉得谣言毫无根据,baseless“没有依据的”。

答案:B

9.A.investigating  B.searching  C.negotiating  D.proving

解析:崔真实向警方抱怨谣言毫无根据,警方当然要调查。她死时警方正在调查此事。

答案:A

10.A.broke up  B.broke out  C.broke down  D.broke in

解析:由她当时的表现可知应选break down,此处指精神方面的瓦解和崩溃。

答案:C

11.A.scolding  B.protesting  C.demonstrating  D.blaming

解析:此处指她抗议网络流言,应用protest。

答案:B

12.A.link  B.availability  C.access  D.connection

解析:此处指宽带服务。access通路,进入,使用的权力。

答案:C

13.A.out  B.up  C.down  D.about

解析:此处是宽带普及造成的后果,bring about“使……产生,造成”。

答案:D

14.A.that  B.what  C.where  D.how

解析:此处是由where引导的定语从句,修饰bulletin boards,where在从句中充当地点状语。

答案:C

15.A.attitudes  B.opinions  C.comments  D.criticism

解析:由常识知,在网上发布的未经证实的、匿名的应是评论,comments指对某事的评论。

答案:C

16.A.with  B.via  C.through  D.about

解析:via“通过”,表方式,后面的名词不用冠词。

答案:B

17.A.online  B.present  C.meanwhile  D.Internet

解析:此处指在线的人身攻击,用online。

答案:A

18.A.react  B.respond  C.reflect  D.reply

解析:此处指“对……的反应”,用respond to。

答案:B

19.A.damaged  B.harmed  C.injured  D.ruined

解析:ruin“毁坏,毁灭(建筑物、前途、名声等)”,符合上下文意。

答案:D

20.A.suffering  B.to suffer  C.to have suffered  D.suffered

解析:先遭受流言蜚语,而后自杀身亡,有先后因果关系,因此用不定式的完成式。

答案:C

试题详情

5.as a result of

试题详情

5.My little brother is unable to go to school ________ ________ ________ ________(由于)the fall from his house.

答案:1.first impressions 2.avoids making 3.with Mrs Chen teaching me 4.would rather 

试题详情

4.He ________ ________(宁愿) keep time for his hobby.

试题详情

3.I’ll do well in the exam ________ ________ ________ ________ ________(由陈老师教我).

试题详情


同步练习册答案