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问题 问答题 简答题

最早证明DNA是遗传物质的经典实验是什么？如何用实验证明DNA的复制是以半保留的方式进行的？

答案

参考答案：

肺炎双球菌的转化实验和噬菌体侵染细菌实验

证明DNA半保留方式复制的实验：15N标记大肠杆菌DNA实验

15N氮源培养基→15N-DNA→14N氮源培养基→离心：14N-15N-DNA→14N氮源培养基继续培养→离心：14N-DNA，14N-15N-DNA

多项选择题

动脉血标本采集常用采血部位（）

A、桡动脉

B、股动脉

C、肱动脉

D、足背动脉

E、腘动脉
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单项选择题


What does the speaker mean a. He cooperated with his friends and set up a business together. b. He was given a lot of advice by his friends in setting up his own business. e. His friends gave him much financial support in setting up his own business. d. His friends encouraged him to set up his own business.
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