【单选题】___________ 是指 当双链 DNA分子的一条链上产生切口时,E.coli DNA聚合酶I就可将核苷酸连接到切口的3'羟基末端。同时该酶具有从5'→3'的核酸外切酶活性,能从切口的5'端除去核苷酸。由于在切去核苷酸的同时又在切口的3'端补上核苷酸,从而使切口沿着DNA链移动,用放射性核苷酸代替原先无放射性的核苷酸,将放射性同位素掺入到合成新链中。
【简答题】原核生物转录时,首先由 识别并结合到DNA上的 ,延伸阶段由 催化 键的形成,转录的终止信号是 ,它是由 辅助识别的。
【多选题】列入《世界遗产名录》风景名胜,其中属文化与自然双重遗产的有( )。
【单选题】is typically used to refer to the study of a particular idea or concept within many cultures. The goal of such investigations is to conduct a series of intercultural analyses in order to compare on cu...
A.
Interethnic communication
B.
Interracial communication
C.
Cross-cultural communication
D.
Intercultural communication
【多选题】列入《世界遗产名录》风景名胜,其中属文化与自然双重遗产的有( )
【简答题】J. R. Firth's main approach to the notion of function in context was by means of concept system. People refer to his theory as ______ theory.
【多选题】列入《世界遗产名录》风景名胜,其中属文化与自然双重遗产的有( )。