基因工程的操作步骤:①使目的基因与运载体相结合②将目的基因导入受体细胞③检测目的基因

题型:单项选择题

问题:

基因工程的操作步骤:

①使目的基因与运载体相结合

②将目的基因导入受体细胞

③检测目的基因的表达是否符合特定性状要求

④提取目的基因。

正确的操作顺序是()

A.③②④①

B.②④①③

C.④①②③

D.③④①②

考点:高中生物基因工程、生物技术的安全性和伦理问题基因工程、生物技术的安全性和伦理问题题库
题型:单项选择题
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题型:单项选择题

阅读理解。

     Yesterday Paul had a busy day. In the morning he cooked some noodles for his family. He went to visit

his aunt at 9:30. In the afternoon he played soccer ball with his classmates. After that he cleaned the room

because it was dirty. He was a little tired,but very happy. After dinner he did his homework. Then he watched

TV for about two hours. He went to bed at nine o'clock.

根据短文内容,判断下列句子正(T)误(F).

( )1. Paul had a busy and happy day off.

( )2. In the morning he cooked some hamburgers for his family.

( )3. In the afternoon he played soccer ball with his parents.

( )4. He cleaned his room in the afternoon.

( )5. He watched TV first then he did his homework.

题型:单项选择题

古罗马与古希腊相比,在政治制度上最大贡献在(   )

A.建立了当时世界上最民主的政体

B.创立了“轮番而治”的民主运作方式

C.实现了君主制到共和制的转变

D.制定了一系列法律制度

题型:单项选择题

从实践效果来看,业主委员会制度对物业管理的发展起到一定的()作用。

A.推动

B.促进

C.决策

D.监督

题型:单项选择题

下列代码的执行结果是( )。
class NextLetter
public static void main(String[ ]args)
char c="a";
System.out.println("The next character is"+ + + c +".");

A.a

B.b

C.c

D.a+c

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