Question

Why are viruses considered as the border line of living and living?

Answer 1

Its because viruses exhibit both the characteristics of living and non-living
1. They possess genetic material and proteins
2. Inherent potential for replication inside the host
3. They can undergo multiplication and mutation
4. Viruses respond to heat, radiations etc

Non-living features:
1.Inability to exhibit properties of life outside host cells
2. Outside host, viruses can even be crystallized like inert particles
3. Absence of protoplasm and cell organelles
4. Viruses can not grow