Question

1. which feature of viruses prevents them from being classified into a kingdom?

they are not pathogens.
they are not virulent.
they are not living organisms.
they are not contagious.

Explanation:

Kingdoms are for classifying living organisms. Viruses lack cellular structure, metabolism, and independent life processes. They are acellular entities that can only replicate inside host cells. So, their non - living nature (as they don't meet the criteria of living organisms like having cells, metabolism, etc.) prevents classification into a kingdom.

Answer:

They are not living organisms.