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  • 克隆

    Multiple identical figures in red shirts representing the concept of cloning.

    Would you like to clone yourself?
    ::你想克隆自己吗?

    Although it's illegal to clone humans in the United States, it is possible to clone many types of animals . What might be the consequences if we allowed human cloning?
    ::尽管在美国克隆人是非法的,但克隆许多种类的动物是可能的。如果我们允许克隆人,结果会是什么?

    Cloning
    ::克隆

    Cloning is the process of creating an exact genetic replica of an organism . The clone’s is exactly the same as the parent’s DNA. Bacteria and other single-celled organisms have long been able to clone themselves through asexual reproduction . Plants can also reproduce asexually. In animals, however, cloning does not happen naturally. In 1997, that all changed when a sheep named Dolly was the first large mammal ever to be successfully cloned. Other animals can now also be cloned in a laboratory.
    ::克隆是创造某种有机体的精确基因复制过程。 克隆与父母的DNA完全一样。 细菌和其他单细胞生物早就能够通过性繁殖克隆自己。 植物也可以进行性繁殖。 但在动物中,克隆不会自然发生。 1997年,当一只叫Dolly的羊成为第一个成功克隆的大型哺乳动物时,克隆就改变了。 其他动物现在也可以在实验室中克隆。

    The process of producing an animal like Dolly starts with a single cell from the animal that is going to be cloned. Below are the steps involved in the process of cloning:
    ::Dolly这种动物的产物过程 是从动物的单细胞开始 从将要克隆的动物的单细胞开始。 下面是克隆过程的步骤:

    1. In the case of Dolly, cells from the mammary glands were taken from the adult that was to be cloned. But other somatic cells can be used. Somatic cells come from the body and are not gametes like or egg .
      ::多利的情况是,哺乳腺的细胞是从要克隆的成年细胞中取出的。但是其他的体细胞也可以使用。体细胞来自身体,不是同卵或蛋一样的数位细胞。
    2. The is removed from this cell. 
      ::从这个单元格中移除。
    3. The nucleus is placed in a donor egg that has had its nucleus removed. The nucleus must be removed from the donor egg to maintain the appropriate chromosome number.
      ::核心放在一个已经去除核心的捐赠者卵中。 核心必须从捐赠者蛋中移除, 以保持适当的染色体数 。
    4. The new cell is stimulated with an electric shock and embryo development begins, as if it were a normal zygote . The zygote is the of a new organism.
      ::新细胞受到电休克的刺激,胚胎发育开始,仿佛是正常的zygote, zygote是新生物体。
    5. The resulting embryo is implanted into a mother sheep, where it continue its development ( Figure ).
      ::由此产生的胚胎被植入母绵羊体内,继续发育(图)。

    The process of cloning, including cell fusion and embryo development steps.

    To clone an animal, a nucleus from the animal’s cells are fused with an egg cell (from which the nucleus has been removed) from a donor, creating a new zygote.
    ::为了克隆动物,动物细胞的核与捐献者的卵细胞(其核已被摘除)结合,产生新的zygote。

    Is Cloning Easy?
    ::克隆容易吗?

    Cloning is not always successful. Most of the time, this cloning process does not result in a healthy adult animal. The process has to be repeated many times until it works. In fact, 277 tries were needed to produce Dolly. This high failure rate is one reason that human cloning is banned in the United States. In order to produce a cloned human, many attempts would result in the surrogate mothers experiencing miscarriages, stillbirths, or deformities in the infant. There are also many additional ethical considerations related to human cloning. Can you think of reasons why people are for or against cloning?
    ::克隆并不总是成功的。 大多数时候,克隆过程并不导致健康的成年动物。这一过程必须重复多次,直到它起作用为止。事实上,需要277次尝试来生产Dolly。这种高失败率是美国禁止人类克隆的原因之一。为了生产克隆人,许多尝试都会导致代孕母亲流产、死胎或婴儿畸形。还有许多其他与人类克隆有关的伦理考虑。你能想到为什么人们赞成或反对克隆的原因吗?

     

    Summary
    ::摘要

    • Cloning, or creating an exact replica of an organism, is now possible for many animals.
      ::对于许多动物来说,克隆,或制造一种有机体的精确复制,现在是可能的。
    • There are many ethical considerations related to human cloning, and it is now illegal to clone humans in the United States.
      ::克隆人的道德考虑有很多,现在在美国克隆人是非法的。

    Review
    ::回顾

    1. Describe the process of creating an animal clone.
      ::描述创建动物克隆的过程 。
    2. What are some reasons why human cloning is banned?
      ::禁止克隆人的理由是什么?