克隆

Nearly all living organisms have parents in which they were reproduced and born through various stages of the life cycle. Whether it is a human being with a mother and a father or a chicken hatching from an egg, most living organisms have male and female parents. Some living organisms also form from one parent such as when a single-celled amoeba splits into two to reproduce offspring.

几乎所有的生命体在生命周期的不同阶段都有双亲孕育和培养。无论是有父母双亲的人类还是从一只从鸡蛋孵化而成的鸡，大部分生命体有两性亲代。也有一些生物体形成于单一亲代，例如单细胞变形虫分裂成两个从而繁衍后代。

However, there is a process which is much different in producing offspring called cloning. Cloning is the process when scientists take DNA from an animal cell and then place it or implant it into an egg cell taken from another animal. Before placing though, the DNA from the cell receiving it is removed.

然而，克隆这种繁殖后代的方法大相径庭。克隆是科学家在动物细胞提取DNA然后将其放入或植入其他动物卵细胞的过程。在植入之前，受体细胞内的DNA被移除。

An example of cloning, which made history in 1997, was when scientists successfully cloned a sheep. The new sheep's name was Dolly, and she was not born in the usual manner. Instead, she became an exact copy of her mother, similar to an identical twin. It would be nearly the same as taking the DNA from the son of a mother, placing the DNA in the egg cell of another woman, but first removing the woman's own DNA, and then allow the growth of the new cell in the woman. Nine months later there would be an exact copy of the mother's son born to the woman.

克隆史上的首例是科学家在1997年成功克隆羊。取名为多莉的克隆羊以非常规方式孕育而成。然而，她与其母本完全一致，类似于同卵双生。这与采集儿子母亲的DNA后放入另一个女人的已除去其本身DNA的卵细胞中，然后新细胞的在女人体内生长。九个月后女人便产下与其儿子母亲完全一致的男婴。

In the case of cloning, a father is not needed. In the first successful cloning of an animal the DNA molecule had all of the information needed to create a clone, Dolly. The DNA molecules contains the genetic code, which is basically directions for the new offspring. Normally, a new organism gets half of this code from the father and the other half from the mother. When these two cells are joined together they divide millions of times and then grow into the millions of cells which form the body of the animal. Each cell of the body has a copy of the genetic code and all it would need is an egg cell to grow.

克隆不需要父本。第一个成功的动物克隆中，DNA分子携带了克隆羊多莉所需的所有信息。 DNA分子中包含的遗传密码基本就是新生子代的方向。通常一个新的有机体得到父母亲双方各一半的遗传密码。两个生殖细胞结合后经过上百万次分裂生成数百万个细胞，构成了动物体。体内每一个细胞都复制了遗传密码，而它所需要的不过是孕育其生长的卵细胞。

So with cloning one of those cells is used and then the cell is simply placed in to the egg cell of the carrier. In the sheep example, the carrier was a female sheep. For Dolly, a single cell was used from the udder of her mother. The DNA in her mother's cell was removed and then transferred to an egg cell of another sheep. About five months later Dolly was born without a father and a copy or clone of her mother.

因此克隆就是将亲本的体细胞中的一个植入载体的卵细胞中。利用多莉母亲的乳房的一个细胞，将该细胞的DNA移植到另一只羊的卵细胞。大约五个月后，没有父亲的多莉出生，与其母亲完全一致，是其母的克隆。

Though no humans have ever been fully cloned, human embryos have been cloned. Currently it may not be taking place, but in the future it may happen, but today it is rare. In the movies about Jurassic Park, cloning took place to create the dinosaurs, though it was a fictional movie, much of the science behind the process can be real.

虽然没有完全的克隆人，但曾有克隆的人类胚胎。克隆人目前难以实现，但将来却可能成真，但至今仍然罕见。侏罗纪公园的电影中，克隆用于创造恐龙，虽然这是一个虚构的电影，该过程后的科学大多是真实的。

Though there are fully developed human clones, other fully developed animals have been cloned besides sheep. They include the rhesus monkey, pig, cattle, cat, rabbit, deer, horse, a few others, and of course mice. Cloning also involves many, many failed attempts before it becomes successful. For instance, Dolly the sheep was not born until after 276 failed attempts. The only true successful cloning takes place when identical twins are born, but they came from a father and a mother. The cloned animals may also experience health problems.

尽管有发育完全的人类克隆，除了多莉羊外其他发育完全的动物克隆，如猕猴，猪，牛，猫，兔，鹿，马等等，当然也有老鼠。克隆成功前还有很多失败的尝试。例如，多莉是276失败的尝试后才出生的。唯一真正成功的克隆是同卵双胞胎，但他们是源于同父同母。克隆动物也可能会遭受健康问题。

In summary, cloning is basically creating another organism without the father involved, and the clone is an exact copy of the mother with the same genetic code. However, if cloning ever became 100% successful, the clones may look alike, but it would not mean they would behave in the same way.

总之，克隆基本上就是不需要父方生育后代且后代完全复制起母亲。但是，100％成功的克隆，即使外表相似，但并不意味着它们的行为会一致。