来自《耶鲁大学开放课程：生物医学工程探索 第3集 第3集》

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  the whole length of the DNA would be to form two identical,
  将生成两条完全一样的
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  double stranded DNA molecules.
  双链DNA分子
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  Now the book talks in more
  书上有更详细的描述
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  detail about this and you can read about it.
  你们可以在课后阅读
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  Polymerase needs a primer and that turns out to be important.
  聚合酶需要引物 这点非常重要
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  A primer is a short RNA sequence or DNA sequence
  引物是一段短的RNA或者DNA序列
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  that gets sort of the process of replication jump started,
  引物是整个复制的起点
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  and that's just because of
  因为DNA聚合酶的
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  the biological properties of DNA polymerase
  生物特性
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  that that primer's needed.
  引物在复制过程是必不可少的
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  Synthesis always occurs in one direction
  DNA复制过程是单向的
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  and that makes sense to you now
  现在你们该明白原因了