题干

噬菌体侵染细菌实验中,在细菌体内合成蛋白质正确的叙述是(   )

A:原料、模板和酶来自细菌

B:模板和酶来自噬菌体,核糖体和氨基酸来自细菌

C:指导蛋白质合成的DNA来自细菌,核糖体、氨基酸原料和酶来自噬菌体

D:指导蛋白质合成的DNA来自噬菌体,核糖体、氨基酸原料和酶来自细菌

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答案(点此获取答案解析)

D

同类题4

   Ellen Parker was worried about her health. She could not walk very quickly and it was difficult for her to climb stars. She was soon out of breath (气喘吁吁).
   “I suppose I had better go to the doctor,” she thought.
   She went to the doctor and told him her problem.
   “I'm not surprised at all,” he said. “It's obvious what your problem is.”He looked her over then gave her some advice.“If you don't do what I say, Mrs. Parker," he said, "you will have a heart attack. It could kill you.”
   Ellen Parker was very worried as she left the doctor's. She knew that she had to take his advice but it would not be easy and it would take time.
   The next day she went shopping. The first shop she went into was a butcher's shop (肉铺).“I'd like ten pounds of steak (牛排), please,” she said.“Certainly, madam,” the butcher replied and went into the cold room and found a large piece of steak. He brought the huge piece of meat back into the shop and put it on the scale (天平).
   “That's just under ten pounds,"he said.
   “That big enough," Mrs. Parker said.
   The butcher worked out the price.
   “At $4.99 a pound that will be $49.50, please. Would you like me to cut it up into smaller pieces for you?”
   “Oh, I don't want to buy the meat,"Mrs. Parker said.
   “If you don't want to buy it," the butcher replied angrily, "why did you ask me to get it for you?”
   “My doctor told me that I am over-weight and I have to lose ten pounds. I wanted to see what ten pounds of meat looked like.”