2022八下新目标43期英语周报答案

22.(16分,除标注外,每空2分)(1)7(2)红眼对白眼为显性,但灰体与黑体的显隐性关系无法确定(3)3等位基因A/a位于常染色体上,D/d位于X染色体上;等位基因D/d位于常染色体上,A/a位于X染色体上(4)统计F1的眼色和体色的性状分离比是否存在性别差异(答案合理即可)F1的眼色和体色的性状分离比均不存在性别差异若F1眼色的性状分离比不存在性别差异,体色的性状分离比存在性别差异,则等位基因A/a位于常染色体上,D/d位于X染色体上;若F1眼色的性状分离比存在性别差异,体色的性状分离比不存在性别差异,则等位基因A/a位于X染色体上,D/d位于常染色体上(4分)【解析】(1)根据题干信息“2n=16”可知,该昆虫产生的正常配子中有7条常染色体和1条性染色体(2)红眼(9)×红眼(),子代中红眼:白眼=3:1,由此可推知红眼对白眼为显性;灰体(9)×黑体(d),子代中灰体:黑体=1:1,相当于测交,而测交不能用于显隐性的判断(3)根据“F1中红眼灰体:红眼黑体:白眼灰体:白眼黑体=3:3:1:1”可知,等位基因A/a和D/d的遗传遵循基因的自由组合定律。据此判断,等位基因A/a和D/d所在染色体的情况有3种可能性,即等位基因A/a和D/d位于两对常染色体上;等位基因A/a基因A/a和D/d位于两对常染色体上;等位基因A/a位于常染色体上,D/d位于X染色体上;等位基因D/d位于常染色体上,A/a位于X染色体上(4)为了确定等位基因A/a和D/d所在染色体的情况,最简单可行的方法是统计F1的眼色和体色的性状分离比是否存在性别差异。

短文改错This evening my father was at a grocery store, where is often crowded. A woman next to with him hadwhiclocked her keys and her baby in her vehicle. Several store clerks had tried to help her but in vain, and he did notshehave the money for a tow truck(E4). My father called a friend of his who is the tow truck driver. It wasalate in the evening and he were having dinner with his family. Therefore, he immediately agreed a drive to helpwasHowevertothe woman. My father then gave the driver twenty dollars and all ended good. The woman was quite moving andwemovednearly burst into teartears

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