Question

Are they organisms; that is, are they alive? What role did viruses play in the evolution of life? What are their distinctive biological characteristics? How can particles so small, simple, and seemingly insignificant be causing disease and death? What is the connection between viruses and cancer?

Answer 1

Yes viruses are organisms and they are not alive outside host. Once it enters the host only it becomes alive

Some viruses are lysogenic viruses and it gets integrated into other organisms host genome and thereby creates evolution or new characters by inserting new genes

3)They are able to replicate by thier own but only inside the host

Some viruses has the ability to connect convert it's genome into DNA to RNA viseversa

Some viruses gets integrated into host genome

4) Eventhough virus are simple and small they attcak the human immuno system and thereby body cannot work against other diseases and also they localize in a particular tissue and replicate and kills the cell to move to adjacent cell and causes damage of organ and death

5. Some viruses such as HPV and HCV integrates into host genome where genes that are responsible for cell cycle regulation (p53 , etc) gets disrupted and leads to excessive cell division and cancer