【单选题】进入50年代以后,管理理论出现了一种( )的趋势。
【判断题】《会计档案管理办法》规定:各级人民政府财政部门和档案行政管理部门共同负责会计档案工作的指导、监督和检查。
【判断题】反义RNA和RNAi均用于抑制目的基因表达。( )
【简答题】mRNA水平对蛋白水平的影响被称作RNA干扰(RNAi)。
【单选题】在二元合金相图中,三相平衡共存时,必定是一条水平线,该水平线 一定与 以一点接触。
【单选题】( )共同负责会计档案工作的指导、监督和检查。
【多选题】How can RNA Interference (RNAi) be used to study the function of genes?
A.
One of the fastest and easiest ways to silence genes in cells and organisms is via RNA interference (RNAi). Discovered in 1998, RNAi exploits a natural mechanism used in a wide variety of plants and animals to protect themselves against infection with certain viruses and the proliferation of mobile genetic elements. The technique involves introducing into a cell or organism double-stranded RNA molecules with a nucleotide sequence that matches the gene to be inactivated.
B.
The double-stranded RNA is cleaved and processed by special RNAi machinery to produce shorter, double-stranded fragments called small interfering RNAs (siRNAs). These siRNAs are separated to form single-stranded RNA fragments that hybridize with the target gene’s mRNAs and direct their degradation. In some organisms, the same fragments can direct the production of more siRNAs, allowing continued inactivation of the target mRNAs.
【单选题】在二元合金相图中,三相平衡共存时,必定是一条水平线,每条水平线一定与 以一点接触。