病毒属于非细胞型微生物,依据被膜包绕与否分为包膜病毒和非包膜病毒两大类,依据核酸的类型即可分为RNA病毒和DNA病毒两大类。它是一类最小的致病因子,明显不同于其他微生物,具有以下特征:(1)个体极小,是迄今所知最小的一类生命体。(2)没有细胞结构,由核酸和蛋白质外壳构成。每 Viruses are non-cell-type microorganisms, which are classified into enveloped viruses and non-enveloped viruses according to whether they are enveloped or not. They can be divided into RNA viruses and DNA viruses according to the types of nucleic acids. It is a group of the smallest virulence factors, distinctly different from other microorganisms, with the following characteristics: (1) Individuals are so small that they are by far the smallest known group of living organisms. (2) No cell structure, consisting of nucleic acid and protein shell. each