问题 选择题

下列生物体不具有细胞结构的是(  )

A.细菌

B.植物

C.动物

D.肝炎病毒

答案

病毒同所有生物一样,具有遗传、变异、进化,是一种体积非常微小,结构极其简单的生命形式.病毒没有细胞结构,主要由内部的核酸和外部的蛋白质外壳组成,不能独立生存,只有寄生在活细胞里才能进行生命活动.一旦离开就会变成结晶体.细菌的基本结构有细胞壁、细胞膜、细胞质和DNA集中的区域,没有成形的细胞核,没有叶绿体;植物体、动物体结构功能的基本单位是细胞.肝炎病毒属于动物病毒因此不具有细胞结构.

故选D.

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