第6题: [单项选择]The journalist was brought to court because_______. A. he was working for a British newspaper. B. he published an untrue story. C. the story was published in Britain. D. he was working with other foreign journalists. 参考答案:B
第28题: [单项选择]用普通水平电泳制备染色体DNA酶切图谱时,为了更好地分离大片段的DNA分子,常采用的措施是() A. 提高电压和延长凝胶的长度 B. 降低琼脂糖凝胶的浓度和延长凝胶的长度 C. 降低电压和增高琼脂糖凝胶的浓度 D. 降低电压和降低琼脂糖凝胶的浓度 E. 增高琼脂糖凝胶的浓度和延长凝胶的长度 参考答案:D 答案解析:普通水平电泳制备染色体DNA酶切图谱时,DNA电泳迁移率的对数与凝胶浓度成线性关系,分离<0.5kb的DNA片段所需胶浓度是1.2%~1.5%,分离>10kb的DNA分子所需胶浓度为0.3%~0.7%