why are viruses considered as being at the 'borderline' between living and non living things
Answers
What is the border between living and non-living things? If we consider them two states, is there anything which dwells between these states?
Viruses
They dwell between living and non living. Let me explain how.
The prime quality of a living thing is the capacity to reproduce. Viruses are fastest reproductive beings. The fact they are living is known to us. Now comes the argument as to why they are non living. Characteristic qualities of the non living are: no locomotion, no reproduction, no activity but mere accumulation of mass. The viruses, when facing unfavorable conditions, behave like non living, not for a day or two but centuries. If there was a virus trapped during ice age, it is likely still trapped dormant and lifeless. The moment you give the right conditions it will spring back to life.
when they are inside cell they help living organisms and when they are outside they help non-living organisms