请大家帮忙解决下,“以质粒载体pBR322为例,说明克隆载体的特点”此题答案是怎样的啊?

除了质粒都有的复制序列外.克隆载体一般要有：
1. 酶切插入位点（该质粒多达40个）
2. 筛选基因（抗药基因）,该质粒有2个（amp, tet).
FYI
pBR322 is a plasmid and for a time was one of the most commonly used E. coli cloning vectors. Created in 1977, it was named eponymously after its Mexican creators, p standing for plasmid, and BR for Bolivar and Rodriguez.