题目

   The view over a valley of a tiny village with thatched(草盖的)roof cottages around a church; a drive through a narrow village street lined with thatched cottages painted pink or white; the sight over the rolling hills of a pretty collection of thatched farm buildings __these are still common sights in parts of England. Most people will agree that the thatched roof is an essential part of the attraction of the English countryside.   Thatching is in fact the oldest of all the building crafts practiced in the British Isles. Although thatch has always been used for cottage and20、试回答下列(l)-(2)题。 (1)在一些性状的遗传中,具有某种基因型的合于不能完成胚胎发育,导致后代中不存在该基因型的个体,从而使性状的分离比例发生变化。小鼠毛色的遗传就是一个例子。一个研究小组,经大量重复实验,在小鼠毛色遗传的研究中发现: A.黑色鼠与黑色鼠杂交,后代全部为黑色鼠。 B.黄色鼠与黄色鼠杂交,后代中黄色鼠与黑色鼠的比例为2:1。 C.黄色鼠与黑色鼠杂交,后代中黄色鼠与黑色鼠的比例为1:1。 根据上述实验结果,回答下列问题:(控制毛色的显性基因用A表示,隐性基因用a表示) ①黄色鼠的基因型是____________,黑色鼠的基因型是_____________。 ②推测不能完成胚胎发育的合子的基因型是_______________。 ③写出上述B人两个杂交组合的遗传图解。          (2)回答下列问题:  ①真核生物某因的编码区中能够编码蛋白质的序列称为____________,不能够编码蛋  白质的序列称为________________。  ②一般来说,如果你知道了某真核生物的一条多肽链的氨基酸序列,你能否确定其基  因编码区的DNA序列?为什么?
英语 试题推荐