题型:阅读理解 题类:常考题 难易度:普通
黑龙江省哈尔滨市第六中学2018-2019学年高二下学期英语6月阶段性测试卷
After photographer Monni Must's daughter Miya died, the sad mother adopted her black dog, Billy Bean. As Billy became increasingly weak, the thought of its dying was just more than Must could handle. So she decided to clone the dog. “I feared everyone was going to forget Miya," she said, "and my other daughters thought I had completely lost my mind."
Billy's cells were shipped to ViaGen Pets, a Texas company that provides the cloning service. With more than $50,000, Must picked up a new puppy. "The dog has a real soul and is everything my daughter was—fun, social and kind," she said. "I feel that I still have that touchable connection and not just a spiritual connection.”
Cloning animals is hardly new. But the recent news that singer Barbra Streisand had cloned her dog grabbed international headlines. People for the Ethical Treatment of Animals(PETA) president Ingrid Newkirk issued a statement saying she would love to talk her out of cloning, noting that millions of wonderful dogs are getting old in animal shelters every year or dying in terrifying ways when abandoned.
Normally, a doctor takes a tissue biopsy(组织活检), a piece of skin and muscle about the size of a pencil eraser, from the dog. The next step is to take an egg cell from a donor dog, remove the egg's nucleus, and insert DNA from the pet to be cloned. When an embryo(胚胎)develops, it is transplanted in the body of a mother dog.
In the basic cloning procedure, scientists take an entire adult cell and put it into an egg that's been relieved of its own DNA. The resulting embryo is a clone. However, in many animals, only one in 100 cloned embryos ever leads to a live birth. Some embryos die in the IVF dish or in the mothers bodies. Of those that are born, a few suffer from abnormalities and quickly die. Besides, pet cloning doesn't mean copying everything of your beloved pets.
试题篮