2018-2022英语周报高二课标（xn）答案

短文改错Dad asked me to buy a china flowerpot online, but I did that. A few days later, I received a text messagetelling meA pick it up at a nearby store. I went to get it, but strangely, I heard a clearly noise inside it.toclearopened a parcel, only to find that the plate had been broken into two piece. I instantly contacted witthestore owner and sent a photo to him, where could prove the truth. Soon I got a reply say ,Im sorry, I willwhicsayingsend another one tomorrow. "I had to go home with the breaking plate. The next day, I received a new flower-brokerpot with a perfect plate and I unite the first plate with glue, I have two flowerpots now lunited

21.(14分,除标注外,每空2分)(1)杂交(1分)自交(1分)基因重组(1分)(2)花药离体培养人工诱导染色体数目加倍明显缩短育种年限(3)人工诱导多倍体多倍体(1分)(4)采用射线照射或药剂处理等人工诱变方式【解析】(1)用①AABB和②abb培育出⑤AAb,需分两步走,第一步AABB与abb进行杂交得③AaBb,所以方法I为杂交育种;第二步让AaBb自交,选出符合要求的AAbb和Aab两种后代的个体Ab和Aabb在外观土无法区别,因此需将和Aabb再分别自交,观察后代性状,无分离现象者为AAbb,所以方法Ⅱ为自交,所依据的原理是基因重组。(2)由③AaBb培育成④Ab的常用方法是花粉的离体培养,由④Ab培育成⑤AAbb的方法是将Ab的幼苗用秋水仙素处理,使染色体加倍,即单倍体育种。(3)由③AaBb培育成⑥ Aaaabbbb的方法,也是用秋水仙素处理AaBb的幼苗或种子,使染笆体加倍,AAaaBBbb又被称为多倍体(4)由②abb培育成⑦Aabb,可采用射线照射或药剂处理等人工诱变方式,其依据的原理是在一定的剂量范围内,射线或药剂不能杀死被实验的生物,但能诱发其中一部分个体产生基因突变,使隐性基因a突变为显性基因As

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