Question

Summarize the unique properties of viruses and explain which of these characteristics allows them to function as a parasite

Answer 1

Ans:

Unique properties of viruses:

1. Virus are acellular and self replicating agents.

2. They can grow and multiply intercellularly only in living host (obligate parsites) and remain inert outside the host.

3. The viruses consists two parts: the double or single stranded nucleic acid (DNA or RNA) , surrounded by the protein coat is called capsid.

4. They lack protein synthesis machinery

5. They are smaller than prokaryotic cells

6. They are transmitted from one organism to another very easily.

7. They can attack specific host

8. They have antigenic property.

9. They can be crystallized.

10. They are resistant against antibiotics.

11. They undergo mutation

12. Virus doesn't respite and depends on host enzyme systems for their activity.

Characteristics allows them to function as a parasite:

They grow and multiply only a living cells. They can exist outside the host cell for a long time but remain inert in free state. They become again active after entering living cells. They can not grow in the nutrient medium with supplement of host cell extract, grow only intact living cells, they are obligate parasites. They are smaller among the infective agent, even smaller than prokaryotic cells. They completely depends on host enzyme systems for their activity. They undergo mutation and have antigenic property. During host DNA replication, virus nucleic acid directs host cell to make different parts of viruses which after assembly to form a complete infectious virion particle.