2022英语周报七年级福建答案

was then promoted as taskmaster. After he had earned enough money, he became a bosseventually.After hearing his words, the boy thought a lot. Success can only be born in action. Workinghard is all winners shared and indispensable experience for achieving their dreams in their lives.Actually the contractors experience was just one good example to prove the truth of it. The boyknew that if he wanted to stand out among people, there was no shortcut or alternative but hardwork. Then he thanked the contractor for his reply and said goodbye to him. Leaving theconstruction site of the skyscraper he already had a firm resolution in his mind that he would starthis own journey right then in order to fulfill his dream in time【参考范文】The contractor told the boy that was also how he had got where he was then. Actually thebuilding contractor had once worked hard and outperformed others through his own constantefforts. If he had worn the same shirt just like other workers and hadn t devoted himself toworking, by no means would he have been noticed by his boss. As a matter of fact he wore his redshirt every day and worked arduously. Soon his day came. He obtained his bosss appreciation and

23.(11分,除标注外,每空2分)(1)dabb1/6(2)花色(1分)显性(3)利用红色宽叶植株自交后代发生性状分离,且分离比接近于2:1【解析】(1)根据F1的性状分离比为6:2:3:1(9:3131的变形可知,这两对基因的遗传遵循自由组合彩律,则亲本基因型为AaBb,子代的表现型和基因型为红色窄叶ABB、AaBb,红色宽叶Aabb,白色窄叶aBB、aaBb,白色宽叶abb,故F1中纯合子只有aBB和abb,所占比例为1/12+1/12=1/6。(2)由分析可知,A、a这对等位基因显性纯合时会使受精卵致死说明控制花色的基因具有显性纯合致死效应。(3)①为验证(2)中的推测,最简便的方法是让F1中红色宽叶植株自交,统计子代的表现型及比例。②如果后代出现性状分离比,且红色与白花之比接近2:1,则证明控制花色的基因具有显性纯合致死效应。

以上就是2022英语周报七年级福建答案，更多英语周报答案请关注本网站。