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  • General

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  • 细菌生殖

    A colony of E. coli bacteria, illustrating rapid growth through binary fission.

    How can bacteria reproduce so rapidly?
    ::细菌怎么能这么快的繁殖呢?

    Bacteria can divide very rapidly. This image is of a growing colony of E. coli bacteria. In the right environment, a single E. coli can divide to form a colony of hundreds of bacteria in just a few hours.
    ::细菌可以快速分裂。 这张图显示,在正确的环境中,单种大肠杆菌可以在几个小时内分裂成数百种细菌的聚居区。

    Bacteria Reproduction
    ::细菌生殖

    Bacteria, being single-celled prokaryotic organisms , do not have a male or female version. Bacteria reproduce asexually. In asexual reproduction , the "parent" produces a genetically identical copy of itself.
    ::细菌是单一细胞的孕育生物,没有男性或女性的版本。细菌是性繁殖的。在性生殖中,“父母”产生基因相同的自我复制。

    Binary Fission
    ::二进制纤维

    Bacteria reproduce through a process called binary fission . During binary fission, the chromosome copies itself, forming two genetically identical copies. Then, the cell enlarges and divides into two new daughter cells . The two daughter cells are identical to the parent cell . Binary fission can happen very rapidly. Some species of bacteria can double their in less than ten minutes! This process makes it possible for a tremendous bacterial colony to start from a single cell.
    ::细菌通过一个叫做二进制裂变的过程繁殖。 在二进制裂变期间, 染色体复制了它本身, 形成两个基因相同的副本。 然后, 细胞扩大并分成两个新的女儿细胞。 两个女儿细胞与母细胞完全相同 。 二进制裂变可以很快发生。 一些细菌可以在不到10分钟内翻倍 ! 这个过程使得一个巨大的细菌细胞从一个细胞开始成为可能 。

    Exchanging DNA
    ::交换DNA

    Are there male and female bacteria? Of course the answer is no. So, sexual reproduction does not occur in bacteria. But not all new bacteria are clones . This is because bacteria can acquire new . This process occurs in three different ways:
    ::是否有男性和女性细菌?当然答案是否定的。因此,性生殖不会在细菌中发生。但并非所有新的细菌都是克隆的。这是因为细菌可以获得新的。这一过程以三种不同的方式发生:

    1. Conjugation : In conjugation, DNA passes through an extension on the surface of one bacterium and travels to another bacterium ( Figure ). Bacteria essential exchange DNA via conjugation.
      ::结合:在结合过程中,DNA在一种细菌的表面通过延伸,然后到另一种细菌(图)。
    2. Transformation : In transformation, bacteria pick up pieces of DNA from their environment.
      ::转化:在转化中,细菌从环境中提取了DNA碎片。
    3. Transduction : In transduction, that infect bacteria carry DNA from one bacterium to another.
      ::转导:在转导中,感染细菌的细菌将DNA从一个细菌传到另一个细菌。

    Electron microscope image showing two bacteria exchanging DNA through a conjugation extension.

    Bacteria can exchange small segments of DNA through conjugation. Notice two bacterial cells are attached by a short extension. DNA can be exchanged through this extension.
    ::细菌可以通过交配交换少量的DNA。注意两个细菌细胞通过短暂的延伸附着。DNA可以通过这一延伸交换。

    Summary
    ::摘要

    • Bacteria reproduce by binary fission, resulting in two daughter cells identical to the parent cell.
      ::细菌通过二进制裂变繁殖,产生两个与母细胞相同的女儿细胞。
    • Bacteria can exchange DNA through the processes of conjugation, transformation, or transduction.
      ::细菌可以通过交融、转化或移植过程交换DNA。

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    • Asexual Reproduction at (1:03)
      ::性生殖(1:03)
    1. There are approximately 7 billion humans on the planet. How long would it take some bacteria to make 7 billion copies of themselves?
      ::地球上大约有70亿人。 需要多久,一些细菌才能制造出70亿的复制品?

    Review
    ::回顾

    1. Describe how bacteria reproduce?
      ::描述细菌是如何繁殖的?
    2. How do bacteria exchange DNA?
      ::细菌如何交换DNA?
    3. What is binary fission?
      ::二进制裂变是什么?
    4. What is transformation involving bacteria?
      ::什么是涉及细菌的转变?