Enveloped viruses have one or more lipoprotein layers surrounding the nucleocapsid.有被膜的病毒在核衣壳外面还有一个或多个脂蛋白层。
The nucleocapsid is arranged in a symmetric fashion, with a precise number and arrangement of structural subunits surrou核衣壳以一种对称方式排列，病毒核酸外的结构亚单位有着精确的数目和排列。