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ss t h at r e q u ir e s t r ial and e r r o r and se ve r al ge n e r at ion s of b r e e d in lo n in g t e c h n ologies m igh t r e d u c e t h e t im e n e e d e d t o m ake a t r ans ge n ic a n im al m odel. Unit 3 Science and nature S t e m c e ll s ar e r e sp ons ib le f or d e ve lop i n g , m ai n t ain in g and r e p air in g t h e b ody t h r ough out li f e .Re se ar c h e r s ar e c u r r e n t l y look in g u p c lon in g as a w ay t o c r e a t e ge n e t ica ll y d e f in e d h u m an s t e m c e ll s f or r e se ar c h and m e d ica l p u r p ose s. Have you see n Jur assic Park? In t h is f e at u r e f il m , sc ientist s u s e DN A p r e se r ve d f or t e n s of m il li ons of ye ar s t o c lon e d in osa u r w e r e ally clone din osa u r s? In t h e or y? Y e w e ll p r e se r ve d sou r c e of DN A f r o m t h e e xt in c t d in osau r , a n d a c losely r e lat e d sp e c ies , c u r r e n t ly li vin g ,t h at c oul d se r ve as a su r r ogat e ( 替代的 ) m ot h e r . Unit 3 Science and nature In r e ality? Pr obab ly n ot .It ’ s n ot li k e ly t h at d in osau r DN A c oul d su r vive u n d am age d f or su c h a lon g t ime .How e ve r ,sc ientist s h ave t r ied t o c lon e sp e c ies t h at b e c a m e e x t in c t m o r e r e c e n t ly , u si n g DN A f r o m w e ll 173。 Re ading — W ar m i ng U p Ⅰ 重點(diǎn)單詞 1 . ___________ adj . 精確的 , 準(zhǔn)確的 2 . ___________ v t . 克隆 n . 克隆出來(lái)的動(dòng)物或植物 3 . ___________ n . 意圖 , 目的;企圖 4 . ___________ n . 憂(yōu)慮 , 焦慮 , 不安 5 . ___________ v t . 收養(yǎng) , 領(lǐng)養(yǎng);采納 , 采用 6 . ___________ adj . 合法的 , 法律許可的 e x a c t c lo ne int e nt io n a nx ie t y a do pt le g a l 7 . ____ ___ _______ n . 結(jié)果 , 后果 8 . _