问题 单项选择题

某女性患红绿色盲,下列说法正确的是(不考虑基因突变)()

A.该女性一定遗传了其外祖父的色盲基因

B.该女性一定遗传了其祖母的色盲基因

C.该女性与正常男性结婚,儿子不一定患色盲

D.该女性的女儿一定是色盲基因携带者

答案

参考答案:B

解析:

色盲是伴X染色体隐性遗传病,女性色盲患者的基因型为XbXb。该女性的色盲基因一个来自父亲,一个来自母亲,而她父亲的色盲基因肯定来源于其祖母,她母亲的色盲基因可能来自其外祖父,也可能来自其外祖母。该女性的色盲基因一个会遗传给儿子和女儿,所以其儿子肯定是色盲患者,而其女儿可能是携带者,也有可能是患者。故选B

考点:本题考查伴性遗传。

点评:本题以色盲为素材,考查伴性遗传的相关内容,意在考查考生的理解判断能力,属于容易题。

单项选择题 A1/A2型题
完形填空
It was raining. I went into a café and asked for a coffee. ____ I was waiting for my drink, I realized there were other people in the place, but I sensed ____. I saw their bodies, but I couldn’t feel their souls ____ their souls belonged to the ____.
I stood up and walked _______the tables. When I came to the biggest computer, I saw a thin, small man _____ in front of it. “I’m Steve,” he ______ answered after I asked him a couple of times what his name was. “I can’t talk with you. I’m ____,” he said. He was chatting online and, ____, he was playing a computer game – a war game. I was ______.
Why didn’t Steve want to talk with me? I tried ____ to speak to that computer geek (怪人),____ not a word came out of his mouth. I touched his shoulder, but no reaction. I was _____. I put my hand in front of the monitor, and he started to shout, “____!”
I took a few steps back, wondering if all those people in the café were looking at me. I raised my head, and saw nobody showed any interest.
      , I realized that the people there were having a nice conversation with their machines, not with people. They were more interested in having a relationship with the      , particularly Steve. I wouldn’t want to         the future of human beings if they preferred sharing their lives with machines         with people.
I was worried and sank in my thoughts. I didn’t even ____ that the coffee was bad, ____ Steve didn’t notice there was a person next to him.
小题1:
A.BeforeB.SinceC.AlthoughD.While
小题2:
A.painB.lonelinessC.sadnessD.fear
小题3:
A.becauseB.whenC.untilD.unless
小题4:
A.homeB.worldC.netD.café
小题5:
A.besideB.amongC.betweenD.on
小题6:
A.sleepingB.laughingC.sittingD.learning
小题7:
A.finallyB.quicklyC.patientlyD.loudly
小题8:
A.busyB.thirstyC.tiredD.sick
小题9:
A.first of allB.just thenC.at the same timeD.by that time
小题10:
A.surprisedB.delightedC.movedD.frightened
小题11:
A.onceB.againC.firstD.even
小题12:
A.butB.soC.ifD.or
小题13:
A.excitedB.respectedC.afraidD.unhappy
小题14:
A.Shut upB.Enjoy yourselfC.Leave me aloneD.Help me out
小题15:
A.From then onB.At that momentC.In allD.Above all
小题16:
A.computerB.soulC.shopD.geek
小题17:
A.tellB.planC.imagineD.design
小题18:
A.other thanB.instead ofC.except forD.as well as
小题19:
A.pretendB.understandC.insistD.realize
小题20:
A.as ifB.just asC.so thatD.even though