智慧上进2021押题卷五答案

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31.D【解析】据题意可知,G或D纯合时有致死效应,因此找不到黏胶眼的纯合品系和展翅的纯合品系,;A错误;分别寻找黏胶眼的杂合品系(Ggd)和展翅的杂合品系(gDd)并独立繁殖保留,可以保留这两个品系,但繁殖过程中会发生性状分离,且后代会出现显性纯合致死个体,B错误;选择既非黏胶眼又非展翅的隐性纯合品系(ggdd),与黏胶眼杂合品系(Ggdd)和展翅杂合品系(ggDd)分别杂交并保留,可达到保留效果,但后代会出现隐性纯合品系(gd),C错误;寻找既为黏胶眼又为展翅且两个显性基因不在同一条Ⅲ号染色体上的品系,基因型为GgDd让其相互杂交并保留,可获得既为黏胶眼又为展翅的个休,最适合长期保留这两种果蝇品系,D正确。

L Hua参考范文My Precious GiftOf all the precious gifts I have received in my life,I value amask from a stranger most.Because of the COVID-19 pandemic,people are required towear masks on buses in China.However,one day,I forgot to wearone when I was heading for a vital exam.While boarding the bus,Iwas stopped by the driver.Realizing that I would be late for the ex-am,I nearly burst into tears.Just at that time,an old lady handedmea mask,telling me not to worry.Thanks to her precious gift,I finallyarrived in time for the exam.The mask represents Chinese people's determination to prevenand control the pandemic,it also reminds me to help others in need.