第十二章单元测试
- The lac operon is optimally expressed (下列那种情况lac乳糖操作子得到最佳表达) （ ）
- A mutation in the operator (O) region of the lac operon would most likely result in (lac乳糖操纵子的操纵子( O )区发生突变极有可能引起) （ ）
- An enhancer sequence (一个增强子序列) （ ）
- A protein causes the acetylation of histones. What effect do you think this will have on a gene in that region? (一种蛋白质引起组蛋白的乙酰化。你认为这会对该区域的某个基因产生什么影响) （ ）
- The advantage of RNAi over other functional genomic techniques is that (RNA干扰相较于其他功能基因组技术的优点在于) （ ）
A:in the absence of both lactose and glucose (乳糖和葡萄糖都缺失时) B:in the absence of lactose and the presence of glucose(存在葡萄糖，缺失乳糖时) C:in the presence of lactose and the absence of glucose(存在乳糖，缺失葡萄糖时) D:in the presence of both lactose and glucose(乳糖和葡萄糖都存在时)
答案:in the presence of lactose and the absence of glucose(存在乳糖，缺失葡萄糖时)
A:constitutive expression of lac, whether or not lactose was present, as the RNA polymerase cannot bind(lac操纵子的组成性表达，无论是否有乳糖存在，阻遏子都不能结合) B:constitutive expression of lac operon, whether or not lactose was present, as the repressor cannot bind(lac操纵子的组成性表达，无论是否有乳糖存在，阻遏子都不能结合) C:reduced expression of lac, as the RNA polymerase cannot bind(由于RNA聚合酶不能结合，降低了lac的表达) D:no change in the expression of lac(没有改变lac的表达)
A:must be located within the gene it affects(必须位于它调控的基因内) B:must be located immediately downstream from the gene it affects(必须位于它调控的基因的下游) C:must be located immediately upstream from the gene it affects(必须位于它调控的基因的上游) D:can be inverted without altering its functional ability(可以被倒置而不改变其功能)
A:It will cause the methylation of that DNA.(DNA甲基化) B:It will cause a decrease in expression.(表达降低) C:It will cause an increase in expression.(表达增强) D:It will permit DNA replication only but will silence the gene.(只允许DNA复制，但会使基因沉默)
A:RNAi can affect many genes at once(RNA干扰可以同时影响多个基因) B:other techniques cannot make specific mutagenic changes (其他技术不能进行特异性的诱变改变) C:RNAi introduces no mutations to the organism(RNA干扰不会使机体产生突变) D:other techniques cannot target single genes(其他技术无法靶向单个基因)
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