英语周报高二课标2020－2021第二期答案

(1)实验思路:让残翅灰身突变体和长翅黑身突变体杂交,得到F1长翅灰身果蝇;让F1长翅灰身雌雄果蝇32.(除注明外,每空2分)杂交,统计后代的表现型及比例。(合理即可,2分)预期结果:若后代长翅灰身残翅灰身:长翅黑身:残翅黑身=9:3:3:1,则基因A/a和基因Bb位于两对同源染色体上;若后代长翅灰身:残翅灰身:长翅黑身:残翅黑身≠9:3:3:1,则基因A/a和基因B/b最可能位于一对同源染色体上。(合理即可,2分)(2)能(1分)若r基因位于常染色体上,白眼突变体雄果蝇的基因型为rr,则可以观察到2个荧光点;若基因位于Ⅹ染色体上,白眼突变体雄果蝇的基因型为XY,则可以观察到1个荧光点(合理即可)荧探针与基因杂交后,观察荧光点所在染色体的形态(合理即可,1分(3)1/63/16或1/8或0

reading, with a confused look on her face. Dannis stoodup,glared at her and shouted, "You stole my wallet! "Thecrowds began to gossip. The girl turned deadly pale, loo-king so restless that words failed her. A strange silencehung in the air. Abruptly, she leaped from the seatParagraph 2The gird ran and Dannis ran after her. After a whileDannis finally grabbed her by the arm. At exactly thatmoment,a policeman approached them and asked aboutwhat happened. Dannis hastened to explain it while the girlfrowned with a shake of her head. After further enquiriesthe policeman took out a wallet and handed it to Dannisadding that someone had found it in the toilet. What a mis-take he had made! Overwhelmed by guilt, Dannis made anapology to the girl第三节One possible versionParagraph 1A seat beside her was empty, and Dannis occupied itHe felt a wave of anger swept over him, "Where is my wal-let? he yelled. The black-haired girl glanced up from her

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