Question

Smallest animal virus is
a) Poxvirus
b) Coliphage
c) Rhinovirus
d) Poliovirus

Answer 1

Hint: Virus is pathogen particles that can cause various diseases. They are usually not alive when present outside the host body. As they enter the host body they get activated and start their machinery using host cells. This leads to the development of symptoms leading to diseases caused by the infecting virus.

Complete answer:
Smallest virus belongs to the family of Picornaviridae. It is about 20-30nm in size. They have limited genetic information on them. Poliovirus belongs to this family. It is the causative agent of polio. The virus enters the body through the mouth or can be spread through the stool of the infected person. It can also be transmitted through air transmission by coughing and sneezing of the infected person.

Polio can be prevented by proper vaccination given to the children at an early age. It is a necessity for children to get the vaccination done as it provides lifetime immunity from the disease. If vaccination is not done then it may lead to paralysis of lower limbs leading to their death.

Additional information:
- Poxvirus has a brick shape and is of size 240-300nm. They have a complex structure and have double-stranded DNA present. They are the causative agents of disease molluscum contagiosum. It causes lesions on the body that are visible. The lesions appear as pinkish-red raised flesh which is small in size. They may become itchy and red as the infection progresses. There is no such treatment but in extreme cases, oral therapy is recommended.
- Rhinovirus is the most common disease-causing virus. It causes common viral infections in humans. It is treated by proper medication. Infection may occur through air transmission of the infected person. Rhinovirus may also get serious and lead to respiratory problems in adults and children.
So the answer is ‘d) Poliovirus’.

Note: Poliovirus has caused huge destruction in India when the proper vaccine wasn’t available to all. Many children were infected and they used to die at an early age. Now there is proper awareness among the individuals and it has led to the eradication of the disease from the country.