题干

下列有关生物技术常用方法的叙述中不正确的是(    )

A:用32P标记的烟草花叶病毒侵染烟草叶片,可以证明烟草花叶病毒的遗传物质是RNA,而不是蛋白质

B:用14C标记的二氧化碳追踪光合作用中的C原子,可以证明C原子的转移途经是:二氧化碳→三碳化合物→糖类

C:用3H标记亮氨酸研究分泌蛋白的合成和分泌过程,可以证明各种生物膜在功能上是紧密联系的

D:格里菲斯将S型肺炎双球菌放在特殊条件下进行体外培养,从中分离出R型活肺炎双球菌,这是基因突变的结果

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D

同类题1

    When I was a teenager growing up in Russia, I wanted to leave school and have my own life. The only way I could do this was to work in the local brick factory in my town, or get married. I was nervous when I told my father I wanted to leave school. I thought he would say, "No! You are going to college." He took me by surprise when he said, “OK. We'll go to the brick factory.”
    Two days later, he took me to the factory. I had a very romantic idea of working in a factory. I had imagined everyone to be friends working together and having fun. I even imagined there would be music and singing. I guess I had watched too many movies as a teenager.
    When we arrived at the factory gate, my father spoke to the guard and one minute later we were inside. My father said, “Take your time. Look around.” I walked around the factory looking at the building, the workers, and listening to the noise. It was horrible. I ran back to my father and said, “I want to go home.”
    He asked me, “What do you think of the factory?”
    "It's terrible," I replied.
    "And marriage is even worse!" he said.
    I went back to school the next day thinking about studying hard so I could get into a good college. I enjoyed studying English so I decided to major in languages at college. Thanks to my father and our trip to the brick factory, I now work at the United Nations and my father is very proud of me. I married a very good man and my life is much better than it would have been working in the factory!