Their acellular nature, absence of metabolic machinery and complete inactivity outside host cells exclude them from cellular kingdoms, revealing that rigid classification boundaries struggle to categorize borderline entities.
Class 9 Science Exploration Chapter 12 Important Questions
SQP from Class 9 Science Chapter 12 Reproduction How Life Continues
(i) Inhibiting features: Viruses lack cell membranes, cytoplasm and metabolic enzymes required for self-sustained energy production and reproduction, remaining inert crystal-like particles until they infect a living host. (ii) Limitations revealed: This exclusion highlights that human classification models rely on strict definitions that nature often transcends, demonstrating that artificial boundaries struggle to categorize entities straddling the threshold between living and non-living matter.
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