使君子

苦楝皮

榧子

鹤草芽

贯众

Like any monumental task, configuring chromosomes for replication requires a certain amount of preparation. For eukaryotic cells, this preparation begins early in G 1 , when DNA is made replication-ready by the recruitment of proteins to the sites along each chromosome where replication will begin. These nucleotide sequences, called origins of replication, serve as landing pads for the proteins and protein complexes that control and carry out DNA synthesis.

One of these protein complexes, called the origin recognition complex (ORC), remains perched on the replication origins throughout the cell cycle. To prepare the DNA for replication, the ORC recruits a protein called Cdc6, whose concentration rises early in G 1 . Together, these proteins load the DNA helicases that will ultimately open up the double helix at the origin of replication. Once this prereplicative complex is in place, the replication origin is loaded and ready to “fire.”

必须创建列，不必创建列族

必须创建列族，不必创建列

列族和列都要创建

列族和列都不必创建

北周外戚杨坚称帝，建立隋朝

李世民 618 年即位，改年号为 “ 贞观 ”

隋炀帝统治残暴，被叛军杀死

李渊称帝，建立唐朝，他就是唐高祖

注意观察尿液的性状、颜色、尿量

保持导尿管通畅,避免受压、扭曲、返折、阻塞等异常情况

观察尿管有无脱出,漏尿

观察留置尿管接触部位的皮肤情况

以上都对

行

列

列族

子表

semi-conservative replication

semi-discontinuous replication

bi-directional replication

RNA primer required