成某些必需的物质 面,不能满足细一菌生长的需要 比较,成分差异太大,细菌不能适应。 10、接第9题。在基本培养基中涂布A和B的混合物,出现少数菌落,这些一菌落的菌株属于以下哪一项() of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities A. met-,bio-,thr-,leu- B. met+,bio+,thr-,leu- C. met-,bio-,thr+,leu+ D. met+,bio+,thr+,leu+ 11、接第9题。已知大肠杆菌营养缺陷型的回复突变率一般低于10 `' o上述菌落出现的原因的可能性有多种,其中可以排除的是()
12、细胞周期中,RNA合成主要发生在() A. G,期 B. G2期 C. S期 D. M期 13、二次大战使用过毒气DFP属于有机烷化合物,该物质能强烈抑制胆碱酯酶,使乙酰胆碱不能分解为乙酸和胆碱。回答下列问题:有机烷化合物抑制胆碱酯酶的原理是()