题干

下列关于基因、性状以及二者关系的叙述,正确的是(    )

A:基因在染色体上呈线性排列,基因的前端有起始密码子,末端有终止密码子

B:基因能够通过复制实现遗传信息在亲代和子代之间的传递

C:性状受基因的控制,基因发生突变,该基因控制的性状也必定改变

D:通过控制酶的合成从而直接控制性状,是基因控制性状的途径之一

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B

同类题5

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Don't talk to me; I'm busy with my iPhone

    Riding a London subway, a person from China will notice one major difference: in London, people do not look at each other. In fact, eye contact is avoided at all times. That's not rudeness—people are just too busy to bother looking.

    Busy doing what, you ask? Well, they're certainly not using the time for a moment of quiet reflection, nor are they reading a book. New technology has replaced quiet habits. Today the only acceptable form of book on the London underground is an e-book.

    Apple company must earn a fortune from London commuters. Since the iPhone was put on market in 2007, over 40,000 --- yes, that's 40,000 “apps” (programs downloaded for the iPhone) have been designed.

    Commuters love them because they are the perfect time-fillers. One “app”, called iShoot, is a game that features tanks. Another one, Tube Exits, tells passengers where to sit on the train to be closest to the exit of their destination. ISteam clouds the iPhone screen when you breathe into the microphone. You can then write in the “steam” on your phone screen.

    For those without an iPhone, another Apple product, the iPod, may be another choice. It's not just teenagers who “plug in” to their music --- iPods are a popular way to pass the time for all ages.

    And if games, e-books and music aren't enough to keep you occupied. Then perhaps you would prefer a film. The development of palm DVD technology means many commuters watch their favorite TV show or film on the way to work. With all this entertainments, it's amazing that people still remember to get off the train.

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