Unit 9 Human Biology Lesson 1 To clone or not to clone? 课件-2023-2024学年高中英语北师大版（2019）选择性必修第三册

Unit 9 Human Biology Lesson 1 To clone or not to clone? What do you know about cloning? What additional information would you like to know? Use the words and phrases to help you. cell to edit genes to develop artificially to break the technical barrier species identical genes to make an exact copy of to produce animal models 人工培育 打破技术障碍 精确复制 生产动物模型 1.现在完成时表示过去的动作或状态持续到现在，对现在造成的影响，可能持续发生下去。 have/has done 2.现在完成进行时表示动作从过去某一时间开始，一直持续到现在，或者刚刚终止，或者可能仍然要继续下去。 have/has+been doing 我已经完成了假期作业。 我一直尽可能地完成假期作业。 3.过去完成时表示过去某一时间或动作之前已经发生或完成的动作，以及此动作对过去的某一时间点造成的影响。had done 4.过去完成进行时表示动作从过去的过去开始一直延续到过去某个时间点。在过去某个时间点时，这个动作可能刚刚停止，也可能仍然在进行。 had been doing 我在春节之前就已经完成了假期作业。 我在来学校之前的那天上午一直在写假期作业。 ...的过程 ①Cloning is the process of making an exact copy of a plant or animal and developing it either naturally or artificially. Natural cloning has been going on for generations. For example, gardeners have been using a form of cloning when they take a cutting from a plant and place it in a 世世代代 园丁 go on 发生;进行 要么...要么... 一种形式 when引导时间状语从句 n.(用来插种的)插枝，插条 ...的过程 对...精确复制 suitable medium, such as soil. Another example of natural cloning is identical twins, who are produced from the same egg. 相同的 例如 who引导非限制性定语从句，充当主语，修饰identical twins ②For years, there had been attempts to clone animals artificially. The first successfully cloned animal was a sheep named Dolly in 1996. At first, Dolly grew normally, but later she developed an illness (that is more normally found in much older animals.) She lived for six and a half years, 起初 much修饰比较级 患病 attempt to do sth.试图做某事 过去分词作后置定语 that引导定语从句，修饰illness only half the life of the sheep (from which she was cloned.) After Dolly, scientists have cloned more than 20 mammal species, including camels, cattle, deer, dogs, goats and mice. However, they have found a similar pattern of health problems with these other species as well. This has led to 超过 lead to 引起 也 “介词+关系代词”引导的定语从句 相似的健康问题 qu