问题 读图填空题

某校学生在开展研究性学习时,进行人类遗传病方面的调查研究。下图是该校学生根据调查结果绘制的某种遗传病的家系图(显、隐性基因用A、a表示)。请分析回答:

(1)调查人类遗传病时,最好选取群体中发病率较高的_________________基因遗传病,Ⅲ7号个体婚前应进行_________________,以防止生出有遗传病的后代。

(2)通过_________个体可以排除这种病是显性遗传病。若Ⅱ4号个体不带有此致病基因,Ⅲ7和Ⅲ10婚配,后代男孩患此病的几率是___________。

(3)若Ⅱ4号个体带有此致病基因,Ⅲ7是红绿色盲基因携带者,Ⅲ7和Ⅲ10婚配,生下患病孩子的概率是_________。

(4)若Ⅱ3和Ⅱ4均不患红绿色盲且染色体数正常,但Ⅲ8既是红绿色盲又是Klinefecter综合症(XXY)患者,其病因是Ⅱ代中的______号个体产生配子时,在减数第______次分裂过程中发生异常。

(5)题中所涉及的a、b属于非等位基因,那么非等位基因的实质是____________________。

答案

(1)单    遗传咨询

(2)Ⅱ3、Ⅱ4、Ⅲ8   1/4

(3)3/8

(4)3      二

(5)染色体上不同位置控制不同性状的基因

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项.选项中有两项为多余选项.

We are all called upon to make a speech at some point in life, but most of us don’t do a very good job.  1  

So, you have to give a speech and you are terrified. You get nervous, you forget what you want to say, you stumble over words, you talk too long, and you bore your audience. Later you think, “Thank Goodness, it’s over. I’m just not good at public speaking. I hope I never have to do that again.”

Cheer up!  2  Here are some simple steps to take the pain out of speech making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then, gather as many facts as you can on your subject. Spend plenty of your time doing your research. Then spend plenty of your time organizing your material so that your speech is clear and easy to follow. Use as many examples as possible, and use pictures, charts, and graphs if they help you make your points more clearly.   3  Don’t talk over their heads, and don’t talk down to them. Treat your audience with respect. They will appreciate your thoughtfulness.

Just remember: Be prepared. Know your subject, your audience, and the occasion. Be brief.  4  And be yourself. Let your personality come through so that you make person-to-person contact with your audience.

If you follow these simple steps, you will see that you don’t have to be afraid of public speaking. In fact, you may find the experience so enjoyable that you volunteer to make more speeches! You’re not convinced yet?   5  

A.It doesn’t to be that bad.

B.Take several deep breaths before your speech.

C.This article gives some advice on how to give good speech.

D.Say what you have to say and then stop.E. Don’t say what you aren’t familiar with.

F. Never forget your audience.

G. Give it a try and see what happens.

单项选择题