问题 单项选择题

下列实例与所利用的技术或原理不相符合的是()

A.转基因抗虫棉的培育需要利用植物组织培养技术

B.植物组织培养过程依据的原理是植物细胞具有全能性

C.原生质体融合和动物细胞融合利用了细胞膜的选择透过性

D.植物愈伤组织的形成和杂交瘤细胞的培养都与细胞分裂有关

答案

参考答案:C

解析:本题综合考察了植物细胞工程的相关知识。植物转基因技术常常是把目的基因转入到离体受精卵细胞或愈伤组织细胞中,转了基因的细胞需要经过植物组织培养过程,变成完整植株,培育出定向变异的新品种;植物的器官、组织、细胞,在一定条件下能通过植物组织培养技术培育成完整的植株,原因是植物细胞携带一套完整的遗传信息,能使其后代发育成一个完整的个体,即具有全能性;原生质体融合和动物细胞杂交过程中,首先是融合细胞的膜的融合,因此利用了膜的流动性等原理;愈伤组织是外植体细胞脱分化恢复分裂能力分裂而形成的细胞群;通过培养杂交瘤细胞使其不断有丝分裂(细胞克隆的过程),产生特异性强的抗体,所以D是正确的,本题答案为C。

单项选择题
阅读理解

Depression(抑郁症)is a serious problem today.Depression causes workers to be unproductive,causing companies and countries to lose billion of dollars.One expert says that depression is like cancer because it is “widespread, costly and deadly”.Depression hits one person in five around the world.

Although people have believed depression to be a problem among the rich and educated,studies show that depression is a problem among everyone.Over any six-month period, between five to seven percent of the world’s population will be suffering from a serious depression.

Suicide(自杀)rates among people suffering from the disease in its extreme, or clinical form were 80 percent higher than in the population at large, and sufferers were four times more likely to have heart attacks.People who suffer from depression often have problems sleeping,getting up on time,and doing work productively.

Depression, which researchers agree has its origin in the genes(基因),brings loss of confidence and ability to concentrate, making it possible for employees and managers to work efficiently.

Depression is made more serious in China by Chinese’s inability to face it.Many people believe that depressed people are either weak or lazy.Besides,there is no good treatment,with few specialists available.

“Most patients in China just don’t get help,” a Chinese doctor says.“In my hospital,I have

to see 30 or 40 patients in a morning,and just have time to say ‘Hello,how do you feel ?…’”

In Western countries,people are not afraid to admit that they have depression,but most do not tell it to their boss,because they fear that their boss would fire them.

“In my experience,aging bosses are the most willing to admit they have it, because they feel

the most secure about themselves, ” an American doctor says.

Hopefully,in the near future,people around the world will be able to admit that they have depression so that they can get the right treatment.

小题1:Which of the following is TRUE according to the passage?

A.It is widely believed that everyone may suffer from depression.

B.Depression brings great problems to its sufferers in their life and work.

C.Depression is a commonly-existing problem only in rich countries.

D.The poorer and the less educated a person is,the less he will suffer from depression.小题2:Compared to normal people,depressed people are likely to be________.   

A.very unconfident and often absent-minded

B.easy to avoid being hit by heart attacks

C.working efficiently and productively

D.either weak or lazy小题3:Depression becomes more serious in China because of_________.

A.the understanding of the problem

B.the lack of treatment and doctors

C.their unwillingness to tell it to their boss

D.the doctors’ careless work小题4:What can we infer from the passage?

A.People are suffering from depression because of the shortage of specialists.

B.The aging bosses around the world dare to say they are depressed.

C.More and mote patients will turn to specialists for help

D.Western people are braver than Chinese people